Bump version: v1.5.3

Update CPython 3.8 from 3.8.3 to 3.8.4

.circleci/prepare.sh

@@ -1,6 +1,8 @@
+set -o errexit
+set -o xtrace
+
 $PYTHON --version
 $PYTHON -m pip --version
-$PYTHON -m pip install -q --user --ignore-installed --upgrade virtualenv
 $PYTHON -m virtualenv -p $PYTHON venv
 venv/bin/python -m pip install -r requirements-dev.txt
 venv/bin/python -m pip freeze

.github/auto-merge.yml

@@ -0,0 +1,7 @@
+# config file for https://github.com/bobvanderlinden/probot-auto-merge
+
+# no approvals required, just the label is enough
+minApprovals: {}
+
+requiredLabels:
+- merge when green

.github/workflows/test.yml

@@ -18,8 +18,8 @@ jobs:
         os: [ubuntu-18.04, windows-latest, macos-latest]
         python_version: ['3.7']
     steps:
-    - uses: actions/checkout@v1
-    - uses: actions/setup-python@v1
+    - uses: actions/checkout@v2
+    - uses: actions/setup-python@v2
       name: Install Python ${{ matrix.python_version }}
       with:
         python-version: ${{ matrix.python_version }}
@@ -28,7 +28,7 @@ jobs:
       run: |
         python -m pip install -r requirements-dev.txt
     - name: Install Visual C++ for Python 2.7
-      if: startsWith(matrix.os, 'windows')
+      if: runner.os == 'Windows'
       run: |
         choco install vcpython27 -f -y
     - name: Test cibuildwheel

.pre-commit-config.yaml

@@ -0,0 +1,21 @@
+repos:
+-   repo: https://gitlab.com/pycqa/flake8
+    rev: 3.8.1
+    hooks:
+    - id: flake8
+      pass_filenames: true
+      # this seems to need to be here in addition to setup.cfg
+      exclude: cibuildwheel/resources/
+-   repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v2.3.0
+    hooks:
+    - id: check-yaml
+    - id: check-merge-conflict
+    - id: end-of-file-fixer
+      exclude: cibuildwheel/resources/pinned_docker_images.cfg
+-   repo: https://github.com/pre-commit/mirrors-mypy
+    rev: ''  # Use the sha / tag you want to point at
+    hooks:
+    - id: mypy
+      files: cibuildwheel|test
+      exclude: cibuildwheel/resources

.travis.yml

@@ -35,6 +35,8 @@ jobs:
       language: shell
       before_install:
        - choco install python3 --version 3.6.8 --no-progress -y
+       # Update root certificates to fix SSL error; see http://www.chawn.com/RootCerts.htm
+       - powershell "md C:\temp\certs; CertUtil -generateSSTFromWU C:\temp\certs\RootStore.sst; Get-ChildItem -Path C:\\temp\certs\Rootstore.sst | Import-Certificate -CertStoreLocation Cert:\\LocalMachine\\Root\\ | out-null"
       env:
         - PYTHON=C:\\Python36\\python
 

README.md

@@ -22,11 +22,13 @@ What does it do?
 | CPython 3.6     | ✅ | ✅  | ✅  | ✅ | ✅ | ✅  | ✅  | ✅² |
 | CPython 3.7     | ✅ | ✅  | ✅  | ✅ | ✅ | ✅  | ✅  | ✅² |
 | CPython 3.8     | ✅ | ✅  | ✅  | ✅ | ✅ | ✅  | ✅  | ✅² |
+| CPython 3.9³    | 🛠 | 🛠  | 🛠  | 🛠 | 🛠 | 🛠  | 🛠  |    |
 | PyPy 2.7 v7.3.0 | ✅ |     | ✅  | ✅ |    |     |     |     |
 | PyPy 3.6 v7.3.0 | ✅ |     | ✅  | ✅ |    |     |     |     |
 
 <sup>¹ Not supported on Travis</sup><br>
-<sup>² Beta support until Travis CI fixes <a href="https://travis-ci.community/t/no-space-left-on-device-for-system-z/5954/11">a bug</a></sup>
+<sup>² Beta support until Travis CI fixes <a href="https://travis-ci.community/t/no-space-left-on-device-for-system-z/5954/11">a bug</a></sup><br>
+<sup>³ Python 3.9 is not yet ABI stable, so you shouldn't publish wheels with it yet. But if you want to check that your wheels build on Python 3.9, try our [`python3.9` branch](https://github.com/joerick/cibuildwheel/pull/382)!</sup>
 
 - Builds manylinux, macOS and Windows wheels for CPython and PyPy using Azure Pipelines, Travis CI, AppVeyor, and CircleCI
 - Bundles shared library dependencies on Linux and macOS through [auditwheel](https://github.com/pypa/auditwheel) and [delocate](https://github.com/matthew-brett/delocate)
@@ -77,7 +79,7 @@ env:
     # Note: TWINE_PASSWORD is set to a PyPI API token in Travis settings
 
 install:
-  - python3 -m pip install cibuildwheel==1.4.2
+  - python3 -m pip install cibuildwheel==1.5.3
 
 script:
   # build the wheels, put them into './wheelhouse'
@@ -92,7 +94,7 @@ after_success:
     fi
 ```
 
-For more information, including how to build on Appveyor, Azure, CircleCI, check out the [documentation](https://cibuildwheel.readthedocs.org) and also check out [the examples](https://github.com/joerick/cibuildwheel/tree/master/examples).
+For more information, including how to build on GitHub Actions, Appveyor, Azure Pipelines, or CircleCI, check out the [documentation](https://cibuildwheel.readthedocs.org) and the [examples](https://github.com/joerick/cibuildwheel/tree/master/examples).
 
 Options
 -------
@@ -100,17 +102,20 @@ Options
 |   | Option | Description |
 |---|--------|-------------|
 | **Build selection** | [`CIBW_PLATFORM`](https://cibuildwheel.readthedocs.io/en/stable/options/#platform)  | Override the auto-detected target platform |
-|   | [`CIBW_BUILD`](https://cibuildwheel.readthedocs.io/en/stable/options/#build-skip)  [`CIBW_SKIP`](https://cibuildwheel.readthedocs.io/en/stable/options/#build-skip)  | Choose the Python versions to build |
-| **Build environment** | [`CIBW_ENVIRONMENT`](https://cibuildwheel.readthedocs.io/en/stable/options/#environment)  | Set environment variables needed during the build |
+|   | [`CIBW_BUILD`](https://cibuildwheel.readthedocs.io/en/stable/options/#build-skip)  <br> [`CIBW_SKIP`](https://cibuildwheel.readthedocs.io/en/stable/options/#build-skip)  | Choose the Python versions to build |
+| **Build customization** | [`CIBW_ENVIRONMENT`](https://cibuildwheel.readthedocs.io/en/stable/options/#environment)  | Set environment variables needed during the build |
+|   | [`CIBW_BEFORE_ALL`](https://cibuildwheel.readthedocs.io/en/stable/options/#before-all)  | Execute a shell command on the build system before any wheels are built. |
 |   | [`CIBW_BEFORE_BUILD`](https://cibuildwheel.readthedocs.io/en/stable/options/#before-build)  | Execute a shell command preparing each wheel's build |
 |   | [`CIBW_REPAIR_WHEEL_COMMAND`](https://cibuildwheel.readthedocs.io/en/stable/options/#repair-wheel-command)  | Execute a shell command to repair each (non-pure Python) built wheel |
-|   | [`CIBW_MANYLINUX_X86_64_IMAGE`](https://cibuildwheel.readthedocs.io/en/stable/options/#manylinux-image)  [`CIBW_MANYLINUX_I686_IMAGE`](https://cibuildwheel.readthedocs.io/en/stable/options/#manylinux-image)  [`CIBW_MANYLINUX_PYPY_X86_64_IMAGE`](https://cibuildwheel.readthedocs.io/en/stable/options/#manylinux-image)  | Specify alternative manylinux docker images |
+|   | [`CIBW_MANYLINUX_X86_64_IMAGE`](https://cibuildwheel.readthedocs.io/en/stable/options/#manylinux-image)  <br> [`CIBW_MANYLINUX_I686_IMAGE`](https://cibuildwheel.readthedocs.io/en/stable/options/#manylinux-image)  <br> [`CIBW_MANYLINUX_PYPY_X86_64_IMAGE`](https://cibuildwheel.readthedocs.io/en/stable/options/#manylinux-image)  <br> [`CIBW_MANYLINUX_AARCH64_IMAGE`](https://cibuildwheel.readthedocs.io/en/stable/options/#manylinux-image)  <br> [`CIBW_MANYLINUX_PPC64LE_IMAGE`](https://cibuildwheel.readthedocs.io/en/stable/options/#manylinux-image)  <br> [`CIBW_MANYLINUX_S390X_IMAGE`](https://cibuildwheel.readthedocs.io/en/stable/options/#manylinux-image)  | Specify alternative manylinux docker images |
+|   | [`CIBW_DEPENDENCY_VERSIONS`](https://cibuildwheel.readthedocs.io/en/stable/options/#dependency-versions)  | Specify how cibuildwheel controls the versions of the tools it uses |
 | **Testing** | [`CIBW_TEST_COMMAND`](https://cibuildwheel.readthedocs.io/en/stable/options/#test-command)  | Execute a shell command to test each built wheel |
-|   | [`CIBW_BEFORE_TEST`](https://cibuildwheel.readthedocs.io/en/stable/options/#before-test)  | Execute shell command to prepare test environment |
+|   | [`CIBW_BEFORE_TEST`](https://cibuildwheel.readthedocs.io/en/stable/options/#before-test)  | Execute a shell command before testing each wheel |
 |   | [`CIBW_TEST_REQUIRES`](https://cibuildwheel.readthedocs.io/en/stable/options/#test-requires)  | Install Python dependencies before running the tests |
 |   | [`CIBW_TEST_EXTRAS`](https://cibuildwheel.readthedocs.io/en/stable/options/#test-extras)  | Install your wheel for testing using extras_require |
 | **Other** | [`CIBW_BUILD_VERBOSITY`](https://cibuildwheel.readthedocs.io/en/stable/options/#build-verbosity)  | Increase/decrease the output of pip wheel |
 
+
 Working examples
 ----------------
 
@@ -147,6 +152,46 @@ This is similar to static linking, so it might have some licence implications. C
 Changelog
 =========
 
+### 1.5.3
+
+_19 July 2020_
+
+- 🛠 Update CPython 3.8 to 3.8.3 (#405)
+- 🛠 Internal refactoring of Linux build, to move control flow into Python (#386)
+
+### 1.5.2
+
+_8 July 2020_
+
+- 🐛 Fix an issue on Windows where pyproject.toml would cause an error when
+  some requirements formats were used. (#401)
+- 🛠 Update CPython 3.7 to 3.7.8 (#394)
+
+### 1.5.1
+
+_25 June 2020_
+
+- 🐛 Fix "OSError: [WinError 17] The system cannot move the file to a different
+  disk drive" on Github Actions (#388, #389)
+
+### 1.5.0
+
+_24 June 2020_
+
+- 🌟 Add [`CIBW_BEFORE_ALL`](https://cibuildwheel.readthedocs.io/en/stable/options/#before-all)
+  option, which lets you run a command on the build machine before any wheels
+  are built. This is especially useful when building on Linux, to `make`
+  something external to Python, or to `yum install` a dependency. (#342)
+- ✨ Added support for projects using pyproject.toml instead of setup.py
+  (#360, #358)
+- ✨ Added workaround to allow Python 3.5 on Windows to pull dependencies from
+  pyproject.toml. (#358)
+- 📚 Improved Github Actions examples and docs (#354, #362)
+- 🐛 Ensure pip wheel uses the specified package, and doesn't build a wheel
+  from PyPI (#369)
+- 🛠 Internal changes: using pathlib.Path, precommit hooks, testing
+  improvements.
+
 ### 1.4.2
 
 _25 May 2020_
@@ -169,7 +214,7 @@ _4 May 2020_
 
 _2 May 2020_
 
-- ✨ Deterministic builds. cibuildwheel now locks the versions of the tools it
+- 🌟 Deterministic builds. cibuildwheel now locks the versions of the tools it
   uses. This means that pinning your version of cibuildwheel pins the versions
   of pip, setuptools, manylinux etc. that are used under the hood. This should
   make things more reliable. But note that we don't control the entire build
@@ -199,7 +244,7 @@ _2 May 2020_
 
 _12 March 2020_
 
-- ✨ Add support for building on Github Actions! Check out the
+- 🌟 Add support for building on Github Actions! Check out the
   [docs](https://cibuildwheel.readthedocs.io/en/stable/setup/#github-actions)
   for information on how to set it up. (#194)
 - ✨ Add the `CIBW_BEFORE_TEST` option, which lets you run a command to
@@ -209,9 +254,9 @@ _12 March 2020_
 
 _8 March 2020_
 
-- ✨ Add support for building PyPy wheels, across Manylinux, macOS, and
+- 🌟 Add support for building PyPy wheels, across Manylinux, macOS, and
   Windows. (#185)
-- ✨ Added the ability to build ARM64 (aarch64), ppc64le, and s390x wheels,
+- 🌟 Added the ability to build ARM64 (aarch64), ppc64le, and s390x wheels,
   using manylinux2014 and Travis CI. (#273)
 - ✨ You can now build macOS wheels on Appveyor. (#230)
 - 🛠 Changed default macOS minimum target to 10.9, from 10.6. This allows the
@@ -232,7 +277,7 @@ _8 March 2020_
 
 _7 December 2019_
 
-- ✨ Add support for building manylinux2014 wheels. To use, set
+- 🌟 Add support for building manylinux2014 wheels. To use, set
   `CIBW_MANYLINUX_X86_64_IMAGE` and CIBW_MANYLINUX_I686_IMAGE to
   `manylinux2014`.
 - ✨ Add support for [Linux on Appveyor](https://www.appveyor.com/blog/2018/03/06/appveyor-for-linux/) (#204, #207)
@@ -245,8 +290,8 @@ _7 December 2019_
 
 _10 November 2019_
 
-- ✨ Add support for building Python 3.8 wheels! (#180)
-- ✨ Add support for building manylinux2010 wheels. cibuildwheel will now
+- 🌟 Add support for building Python 3.8 wheels! (#180)
+- 🌟 Add support for building manylinux2010 wheels. cibuildwheel will now
   build using the manylinux2010 images by default. If your project is still
   manylinux1 compatible, you should get both manylinux1 and manylinux2010
   wheels - you can upload both to PyPI. If you always require manylinux1 wheels, you can
@@ -282,7 +327,7 @@ _28 May 2019_
 
 _26 May 2019_
 
-- ✨ Add support for building on Azure pipelines! This lets you build all
+- 🌟 Add support for building on Azure pipelines! This lets you build all
   Linux, Mac and Windows wheels on one service, so it promises to be the
   easiest to set up! Check out the quickstart in the docs, or
   [cibuildwheel-azure-example](https://github.com/joerick/cibuildwheel-azure-example)
@@ -312,8 +357,8 @@ _3 February 2019_
 
 _23 September 2018_
 
-- ✨ Add `CIBW_BUILD` option, for specifying which specific builds to perform (#101)
-- ✨ Add support for building Mac and Linux on CircleCI (#91, #97)
+- 🌟 Add `CIBW_BUILD` option, for specifying which specific builds to perform (#101)
+- 🌟 Add support for building Mac and Linux on CircleCI (#91, #97)
 - 🛠 Improved support for building universal wheels (#95)
 - 🛠 Ensure log output is unbuffered and therefore in the correct order (#92)
 - 🛠 Improved error reporting for errors that occur inside a package's setup.py (#88)

appveyor.yml

@@ -10,6 +10,11 @@ environment:
     - APPVEYOR_BUILD_WORKER_IMAGE: macos-mojave
       APPVEYOR_JOB_NAME: "python37-x64-macos-mojave"
 
+# while pypy libffi dependency is failing the build, allow failures on macos
+matrix:	
+  allow_failures:	
+    - APPVEYOR_BUILD_WORKER_IMAGE: macos-mojave
+
 stack: python 3.7
 
 build: off

azure-pipelines.yml

@@ -42,4 +42,3 @@ jobs:
     - bash: |
         python -m pip install -r requirements-dev.txt pytest-azurepipelines
         python ./bin/run_tests.py
-

bin/run_tests.py

@@ -3,13 +3,18 @@
 import os
 import subprocess
 import sys
+from pathlib import Path
 
 if __name__ == '__main__':
     # move cwd to the project root
-    os.chdir(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+    os.chdir(Path(__file__).resolve().parents[1])
 
     # run the unit tests
-    subprocess.check_call([sys.executable, '-m', 'pytest', 'unit_test'])
+    unit_test_args = [sys.executable, '-m', 'pytest', 'unit_test']
+    # run the docker unit tests only on Linux
+    if sys.platform.startswith('linux'):
+        unit_test_args += ['--run-docker']
+    subprocess.check_call(unit_test_args)
 
     # run the integration tests
     subprocess.check_call([sys.executable, '-m', 'pytest', '-x', '--durations', '0', 'test'])

cibuildwheel/__init__.py

@@ -1 +1 @@
-__version__ = '1.4.2'
+__version__ = '1.5.3'

cibuildwheel/__main__.py

@@ -4,6 +4,7 @@ import sys
 import textwrap
 import traceback
 from configparser import ConfigParser
+from pathlib import Path
 
 from typing import Any, Dict, List, Optional, overload
 
@@ -20,6 +21,7 @@ from cibuildwheel.util import (
     BuildSelector,
     DependencyConstraints,
     Unbuffered,
+    resources_dir,
 )
 
 
@@ -114,31 +116,44 @@ def main() -> None:
                   file=sys.stderr)
             exit(2)
 
-    output_dir = args.output_dir
-    test_command = get_option_from_environment('CIBW_TEST_COMMAND', platform=platform)
-    test_requires = get_option_from_environment('CIBW_TEST_REQUIRES', platform=platform, default='').split()
-    test_extras = get_option_from_environment('CIBW_TEST_EXTRAS', platform=platform, default='')
-    package_dir = args.package_dir
-    before_build = get_option_from_environment('CIBW_BEFORE_BUILD', platform=platform)
-    build_verbosity_str = get_option_from_environment('CIBW_BUILD_VERBOSITY', platform=platform, default='')
-    build_config, skip_config = os.environ.get('CIBW_BUILD', '*'), os.environ.get('CIBW_SKIP', '')
+    package_dir = Path(args.package_dir)
+    output_dir = Path(args.output_dir)
+
     if platform == 'linux':
         repair_command_default = 'auditwheel repair -w {dest_dir} {wheel}'
     elif platform == 'macos':
         repair_command_default = 'delocate-listdeps {wheel} && delocate-wheel --require-archs x86_64 -w {dest_dir} {wheel}'
     else:
         repair_command_default = ''
-    repair_command = get_option_from_environment('CIBW_REPAIR_WHEEL_COMMAND', platform=platform, default=repair_command_default)
-    environment_config = get_option_from_environment('CIBW_ENVIRONMENT', platform=platform, default='')
-    before_test = get_option_from_environment('CIBW_BEFORE_TEST', platform=platform, default='')
 
+    build_config, skip_config = os.environ.get('CIBW_BUILD', '*'), os.environ.get('CIBW_SKIP', '')
+    environment_config = get_option_from_environment('CIBW_ENVIRONMENT', platform=platform, default='')
+    before_all = get_option_from_environment('CIBW_BEFORE_ALL', platform=platform, default='')
+    before_build = get_option_from_environment('CIBW_BEFORE_BUILD', platform=platform)
+    repair_command = get_option_from_environment('CIBW_REPAIR_WHEEL_COMMAND', platform=platform, default=repair_command_default)
     dependency_versions = get_option_from_environment('CIBW_DEPENDENCY_VERSIONS', platform=platform, default='pinned')
+    test_command = get_option_from_environment('CIBW_TEST_COMMAND', platform=platform)
+    before_test = get_option_from_environment('CIBW_BEFORE_TEST', platform=platform)
+    test_requires = get_option_from_environment('CIBW_TEST_REQUIRES', platform=platform, default='').split()
+    test_extras = get_option_from_environment('CIBW_TEST_EXTRAS', platform=platform, default='')
+    build_verbosity_str = get_option_from_environment('CIBW_BUILD_VERBOSITY', platform=platform, default='')
+
+    build_selector = BuildSelector(build_config, skip_config)
+
+    try:
+        environment = parse_environment(environment_config)
+    except (EnvironmentParseError, ValueError):
+        print(f'cibuildwheel: Malformed environment option "{environment_config}"', file=sys.stderr)
+        traceback.print_exc(None, sys.stderr)
+        exit(2)
+
     if dependency_versions == 'pinned':
         dependency_constraints: Optional[DependencyConstraints] = DependencyConstraints.with_defaults()
     elif dependency_versions == 'latest':
         dependency_constraints = None
     else:
-        dependency_constraints = DependencyConstraints(dependency_versions)
+        dependency_versions_path = Path(dependency_versions)
+        dependency_constraints = DependencyConstraints(dependency_versions_path)
 
     if test_extras:
         test_extras = f'[{test_extras}]'
@@ -148,21 +163,13 @@ def main() -> None:
     except ValueError:
         build_verbosity = 0
 
-    try:
-        environment = parse_environment(environment_config)
-    except (EnvironmentParseError, ValueError):
-        print(f'cibuildwheel: Malformed environment option "{environment_config}"', file=sys.stderr)
-        traceback.print_exc(None, sys.stderr)
-        exit(2)
-
-    build_selector = BuildSelector(build_config, skip_config)
-
     # Add CIBUILDWHEEL environment variable
     # This needs to be passed on to the docker container in linux.py
     os.environ['CIBUILDWHEEL'] = '1'
 
-    if not os.path.exists(os.path.join(package_dir, 'setup.py')):
-        print('cibuildwheel: Could not find setup.py at root of package', file=sys.stderr)
+    if not any((package_dir / name).exists()
+               for name in ["setup.py", "setup.cfg", "pyproject.toml"]):
+        print('cibuildwheel: Could not find setup.py, setup.cfg or pyproject.toml at root of package', file=sys.stderr)
         exit(2)
 
     if args.print_build_identifiers:
@@ -171,9 +178,7 @@ def main() -> None:
 
     manylinux_images: Optional[Dict[str, str]] = None
     if platform == 'linux':
-        pinned_docker_images_file = os.path.join(
-            os.path.dirname(__file__), 'resources', 'pinned_docker_images.cfg'
-        )
+        pinned_docker_images_file = resources_dir / 'pinned_docker_images.cfg'
         all_pinned_docker_images = ConfigParser()
         all_pinned_docker_images.read(pinned_docker_images_file)
         # all_pinned_docker_images looks like a dict of dicts, e.g.
@@ -206,12 +211,13 @@ def main() -> None:
         test_command=test_command,
         test_requires=test_requires,
         test_extras=test_extras,
+        before_test=before_test,
         before_build=before_build,
+        before_all=before_all,
         build_verbosity=build_verbosity,
         build_selector=build_selector,
         repair_command=repair_command,
         environment=environment,
-        before_test=before_test,
         dependency_constraints=dependency_constraints,
         manylinux_images=manylinux_images,
     )
@@ -221,8 +227,8 @@ def main() -> None:
 
     print_preamble(platform, build_options)
 
-    if not os.path.exists(output_dir):
-        os.makedirs(output_dir)
+    if not output_dir.exists():
+        output_dir.mkdir(parents=True)
 
     if platform == 'linux':
         cibuildwheel.linux.build(build_options)

cibuildwheel/bashlex_eval.py

@@ -1,17 +1,24 @@
 import shlex
 import subprocess
-
-from typing import Dict, NamedTuple
+from typing import Callable, Dict, List, NamedTuple, Optional, Sequence
 
 import bashlex  # type: ignore
 
+# a function that takes a shell command and the environment, and returns the result
+EnvironmentExecutor = Callable[[str, Dict[str, str]], str]
+
+
+def local_environment_executor(command: str, env: Dict[str, str]) -> str:
+    return subprocess.check_output(shlex.split(command), env=env, universal_newlines=True)
+
 
 class NodeExecutionContext(NamedTuple):
     environment: Dict[str, str]
     input: str
+    executor: EnvironmentExecutor
 
 
-def evaluate(value: str, environment: Dict[str, str]) -> str:
+def evaluate(value: str, environment: Dict[str, str], executor: Optional[EnvironmentExecutor] = None) -> str:
     if not value:
         # empty string evaluates to empty string
         # (but trips up bashlex)
@@ -26,7 +33,7 @@ def evaluate(value: str, environment: Dict[str, str]) -> str:
 
     return evaluate_node(
         value_word_node,
-        context=NodeExecutionContext(environment=environment, input=value)
+        context=NodeExecutionContext(environment=environment, input=value, executor=executor or local_environment_executor)
     )
 
 
@@ -34,40 +41,65 @@ def evaluate_node(node: bashlex.ast.node, context: NodeExecutionContext) -> str:
     if node.kind == 'word':
         return evaluate_word_node(node, context=context)
     elif node.kind == 'commandsubstitution':
-        return evaluate_command_node(node.command, context=context)
+        node_result = evaluate_command_node(node.command, context=context)
+        # bash removes training newlines in command substitution
+        return node_result.rstrip()
     elif node.kind == 'parameter':
         return evaluate_parameter_node(node, context=context)
     else:
-        raise ValueError(f'Unsupported bash construct: "{node.word}"')
+        raise ValueError(f'Unsupported bash construct: "{node.kind}"')
 
 
 def evaluate_word_node(node: bashlex.ast.node, context: NodeExecutionContext) -> str:
-    word_start = node.pos[0]
-    word_end = node.pos[1]
-    word_string = context.input[word_start:word_end]
-    letters = list(word_string)
+    value = node.word
 
     for part in node.parts:
-        part_start = part.pos[0] - word_start
-        part_end = part.pos[1] - word_start
+        part_string = context.input[part.pos[0]:part.pos[1]]
+        part_value = evaluate_node(part, context=context)
 
-        # Set all the characters in the part to None
-        for i in range(part_start, part_end):
-            letters[i] = ''
+        if part_string not in value:
+            raise RuntimeError(
+                'bash parse failed. part "{}" not found in "{}". Word was "{}". Full input was "{}"'.format(
+                    part_string, value, node.word, context.input,
+                )
+            )
 
-        letters[part_start] = evaluate_node(part, context=context)
+        value = value.replace(part_string, part_value, 1)
 
-    # remove the None letters and concat
-    value = ''.join(letters)
-
-    # apply bash-like quotes/whitespace treatment
-    return ' '.join(word.strip() for word in shlex.split(value))
+    return value
 
 
 def evaluate_command_node(node: bashlex.ast.node, context: NodeExecutionContext) -> str:
-    words = [evaluate_node(part, context=context) for part in node.parts]
+    if any(n.kind == 'operator' for n in node.parts):
+        return evaluate_nodes_as_compound_command(node.parts, context=context)
+    else:
+        return evaluate_nodes_as_simple_command(node.parts, context=context)
+
+
+def evaluate_nodes_as_compound_command(nodes: Sequence[bashlex.ast.node], context: NodeExecutionContext) -> str:
+    # bashlex doesn't support any operators besides ';' inside command
+    # substitutions, so we only need to handle that case. We do so assuming
+    # that `set -o errexit` is on, because it's easier to code!
+
+    result = ''
+    for node in nodes:
+        if node.kind == 'command':
+            result += evaluate_command_node(node, context=context)
+        elif node.kind == 'operator':
+            if node.op == ';':
+                pass
+            else:
+                raise ValueError(f'Unsupported bash operator: "{node.op}"')
+        else:
+            raise ValueError(f'Unsupported bash node in compound command: "{node.kind}"')
+
+    return result
+
+
+def evaluate_nodes_as_simple_command(nodes: List[bashlex.ast.node], context: NodeExecutionContext):
+    words = [evaluate_node(part, context=context) for part in nodes]
     command = ' '.join(words)
-    return subprocess.check_output(shlex.split(command), env=context.environment, universal_newlines=True)
+    return context.executor(command, context.environment)
 
 
 def evaluate_parameter_node(node: bashlex.ast.node, context: NodeExecutionContext) -> str:

cibuildwheel/docker_container.py

@@ -0,0 +1,189 @@
+import io
+import json
+import os
+import shlex
+import subprocess
+import sys
+import uuid
+from os import PathLike
+from pathlib import Path, PurePath
+from typing import IO, Dict, List, Optional, Sequence, Union
+
+
+class DockerContainer:
+    '''
+    An object that represents a running Docker container.
+
+    Intended for use as a context manager e.g.
+    `with DockerContainer('ubuntu') as docker:`
+
+    A bash shell is running in the remote container. When `call()` is invoked,
+    the command is relayed to the remote shell, and the results are streamed
+    back to cibuildwheel.
+    '''
+    UTILITY_PYTHON = '/opt/python/cp38-cp38/bin/python'
+
+    process: subprocess.Popen
+    bash_stdin: IO[bytes]
+    bash_stdout: IO[bytes]
+
+    def __init__(self, docker_image: str, simulate_32_bit=False):
+        self.docker_image = docker_image
+        self.simulate_32_bit = simulate_32_bit
+
+    def __enter__(self) -> 'DockerContainer':
+        self.name = f'cibuildwheel-{uuid.uuid4()}'
+        shell_args = ['linux32', '/bin/bash'] if self.simulate_32_bit else ['/bin/bash']
+        subprocess.run(
+            [
+                'docker', 'create',
+                '--env', 'CIBUILDWHEEL',
+                '--name', self.name,
+                '-i',
+                '-v', '/:/host',  # ignored on CircleCI
+                self.docker_image,
+                *shell_args
+            ],
+            check=True,
+        )
+        self.process = subprocess.Popen(
+            [
+                'docker', 'start',
+                '--attach', '--interactive',
+                self.name,
+            ],
+            stdin=subprocess.PIPE,
+            stdout=subprocess.PIPE,
+        )
+
+        assert self.process.stdin and self.process.stdout
+        self.bash_stdin = self.process.stdin
+        self.bash_stdout = self.process.stdout
+
+        # run a noop command to block until the container is responding
+        self.call(['/bin/true'])
+
+        return self
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        self.bash_stdin.close()
+        self.process.terminate()
+        self.process.wait()
+
+        subprocess.run(['docker', 'rm', '--force', '-v', self.name])
+        self.name = None
+
+    def copy_into(self, from_path: Path, to_path: PurePath) -> None:
+        # `docker cp` causes 'no space left on device' error when
+        # a container is running and the host filesystem is
+        # mounted. https://github.com/moby/moby/issues/38995
+        # Use `docker exec` instead.
+
+        if from_path.is_dir():
+            self.call(['mkdir', '-p', to_path])
+            subprocess.run(
+                f'tar cf - . | docker exec -i {self.name} tar -xC {shell_quote(to_path)} -f -',
+                shell=True,
+                check=True,
+                cwd=from_path)
+        else:
+            subprocess.run(
+                f'cat {shell_quote(from_path)} | docker exec -i {self.name} sh -c "cat > {shell_quote(to_path)}"',
+                shell=True,
+                check=True)
+
+    def copy_out(self, from_path: PurePath, to_path: Path) -> None:
+        # note: we assume from_path is a dir
+        to_path.mkdir(parents=True, exist_ok=True)
+
+        subprocess.run(
+            f'docker exec -i {self.name} tar -cC {shell_quote(from_path)} -f - . | tar -xf -',
+            shell=True,
+            check=True,
+            cwd=to_path
+        )
+
+    def glob(self, path: PurePath, pattern: str) -> List[PurePath]:
+        glob_pattern = os.path.join(str(path), pattern)
+
+        path_strs = json.loads(self.call([
+            self.UTILITY_PYTHON,
+            '-c',
+            f'import sys, json, glob; json.dump(glob.glob({glob_pattern!r}), sys.stdout)'
+        ], capture_output=True))
+
+        return [PurePath(p) for p in path_strs]
+
+    def call(self, args: Sequence[Union[str, PathLike]], env: Dict[str, str] = {},
+             capture_output=False, cwd: Optional[Union[str, PathLike]] = None) -> str:
+        chdir = f'cd {cwd}' if cwd else ''
+        env_assignments = ' '.join(f'{shlex.quote(k)}={shlex.quote(v)}'
+                                   for k, v in env.items())
+        command = ' '.join(shlex.quote(str(a)) for a in args)
+        end_of_message = str(uuid.uuid4())
+
+        # log the command we're executing
+        print(f'    + {command}')
+
+        # Write a command to the remote shell. First we change the
+        # cwd, if that's required. Then, we use the `env` utility to run
+        # `command` inside the specified environment. We use `env` because it
+        # can cope with spaces and strange characters in the name or value.
+        # Finally, the remote shell is told to write a footer - this will show
+        # up in the output so we know when to stop reading, and will include
+        # the returncode of `command`.
+        self.bash_stdin.write(bytes(f'''(
+            {chdir}
+            env {env_assignments} {command}
+            printf "%04d%s\n" $? {end_of_message}
+        )
+        ''', encoding='utf8', errors='surrogateescape'))
+        self.bash_stdin.flush()
+
+        if capture_output:
+            output_io: IO[bytes] = io.BytesIO()
+        else:
+            output_io = sys.stdout.buffer
+
+        while True:
+            line = self.bash_stdout.readline()
+
+            if line.endswith(b'%s\n' % (bytes(end_of_message, encoding='utf8'))):
+                footer_offset = (
+                    len(line)
+                    - 1  # newline character
+                    - len(end_of_message)  # delimiter
+                    - 4  # 4 returncode decimals
+                )
+                returncode_str = line[footer_offset:footer_offset+4]
+                returncode = int(returncode_str)
+                # add the last line to output, without the footer
+                output_io.write(line[0:footer_offset])
+                break
+            else:
+                output_io.write(line)
+
+        if isinstance(output_io, io.BytesIO):
+            output = str(output_io.getvalue(), encoding='utf8', errors='surrogateescape')
+        else:
+            output = ''
+
+        if returncode != 0:
+            raise subprocess.CalledProcessError(returncode, args, output)
+
+        return output
+
+    def get_environment(self) -> Dict[str, str]:
+        return json.loads(self.call([
+            self.UTILITY_PYTHON,
+            '-c',
+            'import sys, json, os; json.dump(os.environ.copy(), sys.stdout)'
+        ], capture_output=True))
+
+    def environment_executor(self, command: str, environment: Dict[str, str]) -> str:
+        # used as an EnvironmentExecutor to evaluate commands and capture output
+        return self.call(shlex.split(command), env=environment)
+
+
+def shell_quote(path: PurePath) -> str:
+    return shlex.quote(str(path))

cibuildwheel/environment.py

@@ -1,6 +1,6 @@
 import bashlex  # type: ignore
 
-from typing import Dict, List
+from typing import Dict, List, Mapping, Optional
 
 from . import bashlex_eval
 
@@ -46,9 +46,9 @@ class EnvironmentAssignment:
         self.name = name
         self.value = value
 
-    def evaluated_value(self, environment: Dict[str, str]) -> str:
+    def evaluated_value(self, environment: Dict[str, str], executor: Optional[bashlex_eval.EnvironmentExecutor] = None) -> str:
         '''Returns the value of this assignment, as evaluated in the environment'''
-        return bashlex_eval.evaluate(self.value, environment=environment)
+        return bashlex_eval.evaluate(self.value, environment=environment, executor=executor)
 
     def as_shell_assignment(self) -> str:
         return f'export {self.name}={self.value}'
@@ -61,11 +61,13 @@ class ParsedEnvironment:
     def __init__(self, assignments: List[EnvironmentAssignment]):
         self.assignments = assignments
 
-    def as_dictionary(self, prev_environment: Dict[str, str]) -> Dict[str, str]:
-        environment = prev_environment.copy()
+    def as_dictionary(self,
+                      prev_environment: Mapping[str, str],
+                      executor: Optional[bashlex_eval.EnvironmentExecutor] = None) -> Dict[str, str]:
+        environment = dict(**prev_environment)
 
         for assignment in self.assignments:
-            value = assignment.evaluated_value(environment=environment)
+            value = assignment.evaluated_value(environment=environment, executor=executor)
             environment[assignment.name] = value
 
         return environment

cibuildwheel/linux.py

@@ -1,26 +1,14 @@
-import os
 import platform
-import shlex
 import subprocess
 import sys
 import textwrap
-import uuid
+from os import PathLike
+from pathlib import Path, PurePath
+from typing import List, NamedTuple, Union
 
-from typing import List, NamedTuple, Optional, Union
-
-from .util import (
-    BuildOptions,
-    BuildSelector,
-    get_build_verbosity_extra_flags,
-    prepare_command,
-)
-
-
-def call(args: List[str], input: Optional[Union[str, bytes]] = None, universal_newlines: bool = False) -> None:
-    print('+ ' + ' '.join(shlex.quote(a) for a in args))
-    subprocess.run(
-        args, input=input, universal_newlines=universal_newlines, check=True
-    )
+from .docker_container import DockerContainer
+from .util import (BuildOptions, BuildSelector,
+                   get_build_verbosity_extra_flags, prepare_command)
 
 
 def matches_platform(identifier: str) -> bool:
@@ -47,37 +35,41 @@ def matches_platform(identifier: str) -> bool:
 class PythonConfiguration(NamedTuple):
     version: str
     identifier: str
-    path: str
+    path_str: str
+
+    @property
+    def path(self):
+        return PurePath(self.path_str)
 
 
 def get_python_configurations(build_selector: BuildSelector) -> List[PythonConfiguration]:
     python_configurations = [
-        PythonConfiguration(version='2.7', identifier='cp27-manylinux_x86_64', path='/opt/python/cp27-cp27m'),
-        PythonConfiguration(version='2.7', identifier='cp27-manylinux_x86_64', path='/opt/python/cp27-cp27mu'),
-        PythonConfiguration(version='3.5', identifier='cp35-manylinux_x86_64', path='/opt/python/cp35-cp35m'),
-        PythonConfiguration(version='3.6', identifier='cp36-manylinux_x86_64', path='/opt/python/cp36-cp36m'),
-        PythonConfiguration(version='3.7', identifier='cp37-manylinux_x86_64', path='/opt/python/cp37-cp37m'),
-        PythonConfiguration(version='3.8', identifier='cp38-manylinux_x86_64', path='/opt/python/cp38-cp38'),
-        PythonConfiguration(version='2.7', identifier='cp27-manylinux_i686', path='/opt/python/cp27-cp27m'),
-        PythonConfiguration(version='2.7', identifier='cp27-manylinux_i686', path='/opt/python/cp27-cp27mu'),
-        PythonConfiguration(version='3.5', identifier='cp35-manylinux_i686', path='/opt/python/cp35-cp35m'),
-        PythonConfiguration(version='3.6', identifier='cp36-manylinux_i686', path='/opt/python/cp36-cp36m'),
-        PythonConfiguration(version='3.7', identifier='cp37-manylinux_i686', path='/opt/python/cp37-cp37m'),
-        PythonConfiguration(version='3.8', identifier='cp38-manylinux_i686', path='/opt/python/cp38-cp38'),
-        PythonConfiguration(version='2.7', identifier='pp27-manylinux_x86_64', path='/opt/python/pp27-pypy_73'),
-        PythonConfiguration(version='3.6', identifier='pp36-manylinux_x86_64', path='/opt/python/pp36-pypy36_pp73'),
-        PythonConfiguration(version='3.5', identifier='cp35-manylinux_aarch64', path='/opt/python/cp35-cp35m'),
-        PythonConfiguration(version='3.6', identifier='cp36-manylinux_aarch64', path='/opt/python/cp36-cp36m'),
-        PythonConfiguration(version='3.7', identifier='cp37-manylinux_aarch64', path='/opt/python/cp37-cp37m'),
-        PythonConfiguration(version='3.8', identifier='cp38-manylinux_aarch64', path='/opt/python/cp38-cp38'),
-        PythonConfiguration(version='3.5', identifier='cp35-manylinux_ppc64le', path='/opt/python/cp35-cp35m'),
-        PythonConfiguration(version='3.6', identifier='cp36-manylinux_ppc64le', path='/opt/python/cp36-cp36m'),
-        PythonConfiguration(version='3.7', identifier='cp37-manylinux_ppc64le', path='/opt/python/cp37-cp37m'),
-        PythonConfiguration(version='3.8', identifier='cp38-manylinux_ppc64le', path='/opt/python/cp38-cp38'),
-        PythonConfiguration(version='3.5', identifier='cp35-manylinux_s390x', path='/opt/python/cp35-cp35m'),
-        PythonConfiguration(version='3.6', identifier='cp36-manylinux_s390x', path='/opt/python/cp36-cp36m'),
-        PythonConfiguration(version='3.7', identifier='cp37-manylinux_s390x', path='/opt/python/cp37-cp37m'),
-        PythonConfiguration(version='3.8', identifier='cp38-manylinux_s390x', path='/opt/python/cp38-cp38'),
+        PythonConfiguration(version='2.7', identifier='cp27-manylinux_x86_64', path_str='/opt/python/cp27-cp27m'),
+        PythonConfiguration(version='2.7', identifier='cp27-manylinux_x86_64', path_str='/opt/python/cp27-cp27mu'),
+        PythonConfiguration(version='3.5', identifier='cp35-manylinux_x86_64', path_str='/opt/python/cp35-cp35m'),
+        PythonConfiguration(version='3.6', identifier='cp36-manylinux_x86_64', path_str='/opt/python/cp36-cp36m'),
+        PythonConfiguration(version='3.7', identifier='cp37-manylinux_x86_64', path_str='/opt/python/cp37-cp37m'),
+        PythonConfiguration(version='3.8', identifier='cp38-manylinux_x86_64', path_str='/opt/python/cp38-cp38'),
+        PythonConfiguration(version='2.7', identifier='cp27-manylinux_i686', path_str='/opt/python/cp27-cp27m'),
+        PythonConfiguration(version='2.7', identifier='cp27-manylinux_i686', path_str='/opt/python/cp27-cp27mu'),
+        PythonConfiguration(version='3.5', identifier='cp35-manylinux_i686', path_str='/opt/python/cp35-cp35m'),
+        PythonConfiguration(version='3.6', identifier='cp36-manylinux_i686', path_str='/opt/python/cp36-cp36m'),
+        PythonConfiguration(version='3.7', identifier='cp37-manylinux_i686', path_str='/opt/python/cp37-cp37m'),
+        PythonConfiguration(version='3.8', identifier='cp38-manylinux_i686', path_str='/opt/python/cp38-cp38'),
+        PythonConfiguration(version='2.7', identifier='pp27-manylinux_x86_64', path_str='/opt/python/pp27-pypy_73'),
+        PythonConfiguration(version='3.6', identifier='pp36-manylinux_x86_64', path_str='/opt/python/pp36-pypy36_pp73'),
+        PythonConfiguration(version='3.5', identifier='cp35-manylinux_aarch64', path_str='/opt/python/cp35-cp35m'),
+        PythonConfiguration(version='3.6', identifier='cp36-manylinux_aarch64', path_str='/opt/python/cp36-cp36m'),
+        PythonConfiguration(version='3.7', identifier='cp37-manylinux_aarch64', path_str='/opt/python/cp37-cp37m'),
+        PythonConfiguration(version='3.8', identifier='cp38-manylinux_aarch64', path_str='/opt/python/cp38-cp38'),
+        PythonConfiguration(version='3.5', identifier='cp35-manylinux_ppc64le', path_str='/opt/python/cp35-cp35m'),
+        PythonConfiguration(version='3.6', identifier='cp36-manylinux_ppc64le', path_str='/opt/python/cp36-cp36m'),
+        PythonConfiguration(version='3.7', identifier='cp37-manylinux_ppc64le', path_str='/opt/python/cp37-cp37m'),
+        PythonConfiguration(version='3.8', identifier='cp38-manylinux_ppc64le', path_str='/opt/python/cp38-cp38'),
+        PythonConfiguration(version='3.5', identifier='cp35-manylinux_s390x', path_str='/opt/python/cp35-cp35m'),
+        PythonConfiguration(version='3.6', identifier='cp36-manylinux_s390x', path_str='/opt/python/cp36-cp36m'),
+        PythonConfiguration(version='3.7', identifier='cp37-manylinux_s390x', path_str='/opt/python/cp37-cp37m'),
+        PythonConfiguration(version='3.8', identifier='cp38-manylinux_s390x', path_str='/opt/python/cp38-cp38'),
     ]
     # skip builds as required
     return [c for c in python_configurations if matches_platform(c.identifier) and build_selector(c.identifier)]
@@ -104,194 +96,143 @@ def build(options: BuildOptions) -> None:
         ('pp', 'manylinux_x86_64', options.manylinux_images['pypy_x86_64']),
     ]
 
-    if not os.path.realpath(options.package_dir).startswith(os.path.realpath('.')):
+    cwd = Path.cwd()
+    abs_package_dir = options.package_dir.resolve()
+    if cwd != abs_package_dir and cwd not in abs_package_dir.parents:
         raise Exception('package_dir must be inside the working directory')
 
-    container_package_dir = os.path.join('/project', os.path.relpath(options.package_dir, '.'))
+    container_package_dir = PurePath('/project') / abs_package_dir.relative_to(cwd)
+    container_output_dir = PurePath('/output')
 
     for implementation, platform_tag, docker_image in platforms:
         platform_configs = [c for c in python_configurations if c.identifier.startswith(implementation) and c.identifier.endswith(platform_tag)]
         if not platform_configs:
             continue
 
-        container_name = f'cibuildwheel-{uuid.uuid4()}'
-
         try:
-            shell_cmd = ['linux32', '/bin/bash'] if platform_tag.endswith("i686") else ['/bin/bash']
-            call(['docker', 'create',
-                  '--env', 'CIBUILDWHEEL',
-                  '--name', container_name,
-                  '-i',
-                  '-v', '/:/host',  # ignored on CircleCI
-                  docker_image,
-                  '/bin/bash'])
+            with DockerContainer(docker_image, simulate_32_bit=platform_tag.endswith('i686')) as docker:
+                docker.copy_into(Path.cwd(), Path('/project'))
 
-            call(['docker', 'cp', '.', container_name + ':/project'])
+                if options.before_all:
+                    env = docker.get_environment()
+                    env['PATH'] = f'/opt/python/cp38-cp38:{env["PATH"]}'
+                    env = options.environment.as_dictionary(env, executor=docker.environment_executor)
 
-            call(['docker', 'start', container_name])
+                    before_all_prepared = prepare_command(options.before_all, project='/project', package=container_package_dir)
+                    docker.call(['sh', '-c', before_all_prepared], env=env)
 
-            for config in platform_configs:
-                if options.dependency_constraints:
-                    constraints_file = options.dependency_constraints.get_for_python_version(config.version)
+                for config in platform_configs:
+                    dependency_constraint_flags: List[Union[str, PathLike]] = []
 
-                    # `docker cp` causes 'no space left on device' error when
-                    # a container is running and the host filesystem is
-                    # mounted. https://github.com/moby/moby/issues/38995
-                    # Use `docker exec` instead.
-                    with open(constraints_file, 'rb') as f:
-                        call(
-                            ['docker', 'exec', '-i', container_name, 'sh', '-c', 'cat > /constraints.txt'],
-                            input=f.read(),
-                        )
+                    if options.dependency_constraints:
+                        constraints_file = options.dependency_constraints.get_for_python_version(config.version)
+                        container_constraints_file = PurePath('/constraints.txt')
 
-                call(
-                    ['docker', 'exec', '-i', container_name] + shell_cmd,
-                    universal_newlines=True,
-                    input='''
-                        # give xtrace output an extra level of indent inside docker
-                        PS4='    + '
+                        docker.copy_into(constraints_file, container_constraints_file)
+                        dependency_constraint_flags = ['-c', container_constraints_file]
 
-                        set -o errexit
-                        set -o xtrace
-                        mkdir -p /output
-                        cd /project
+                    env = docker.get_environment()
 
-                        PYBIN="{config_python_bin}"
+                    # put this config's python top of the list
+                    python_bin = config.path / 'bin'
+                    env['PATH'] = f'{python_bin}:{env["PATH"]}'
 
-                        export PATH="$PYBIN:$PATH"
-                        {environment_exports}
+                    env = options.environment.as_dictionary(env, executor=docker.environment_executor)
 
-                        # check the active python and pip are in PYBIN
-                        if [ "$(which pip)" != "$PYBIN/pip" ]; then
-                        echo "cibuildwheel: python available on PATH doesn't match our installed instance. If you have modified PATH, ensure that you don't overwrite cibuildwheel's entry or insert python above it."
-                        exit 1
-                        fi
-                        if [ "$(which python)" != "$PYBIN/python" ]; then
-                        echo "cibuildwheel: pip available on PATH doesn't match our installed instance. If you have modified PATH, ensure that you don't overwrite cibuildwheel's entry or insert pip above it."
-                        exit 1
-                        fi
+                    # check config python and pip are still on PATH
+                    which_python = docker.call(['which', 'python'], env=env, capture_output=True).strip()
+                    if PurePath(which_python) != python_bin / 'python':
+                        print("cibuildwheel: python available on PATH doesn't match our installed instance. If you have modified PATH, ensure that you don't overwrite cibuildwheel's entry or insert python above it.", file=sys.stderr)
+                        exit(1)
 
-                        if [ ! -z {before_build} ]; then
-                            sh -c {before_build}
-                        fi
+                    which_pip = docker.call(['which', 'pip'], env=env, capture_output=True).strip()
+                    if PurePath(which_pip) != python_bin / 'pip':
+                        print("cibuildwheel: pip available on PATH doesn't match our installed instance. If you have modified PATH, ensure that you don't overwrite cibuildwheel's entry or insert pip above it.", file=sys.stderr)
+                        exit(1)
 
-                        # Build the wheel
-                        rm -rf /tmp/built_wheel
-                        mkdir /tmp/built_wheel
-                        pip wheel {package_dir} -w /tmp/built_wheel --no-deps {build_verbosity_flag}
-                        built_wheel=(/tmp/built_wheel/*.whl)
+                    if options.before_build:
+                        before_build_prepared = prepare_command(options.before_build, project='/project', package=container_package_dir)
+                        docker.call(['sh', '-c', before_build_prepared], env=env)
 
-                        # repair the wheel
-                        rm -rf /tmp/repaired_wheels
-                        mkdir /tmp/repaired_wheels
-                        # NOTE: 'built_wheel' here is a bash array of glob matches; "$built_wheel" returns
-                        # the first element
-                        if [[ "$built_wheel" == *none-any.whl ]] || [ -z {repair_command} ]; then
-                            # pure Python wheel or empty repair command
-                            mv "$built_wheel" /tmp/repaired_wheels
-                        else
-                            sh -c {repair_command} repair_command "$built_wheel"
-                        fi
-                        repaired_wheels=(/tmp/repaired_wheels/*.whl)
+                    temp_dir = PurePath('/tmp/cibuildwheel')
+                    built_wheel_dir = temp_dir / 'built_wheel'
+                    docker.call(['rm', '-rf', built_wheel_dir])
+                    docker.call(['mkdir', '-p', built_wheel_dir])
 
-                        if [ ! -z {test_command} ]; then
-                            # Set up a virtual environment to install and test from, to make sure
-                            # there are no dependencies that were pulled in at build time.
-                            pip install {dependency_install_flags} virtualenv
-                            venv_dir=`mktemp -d`/venv
-                            python -m virtualenv --no-download "$venv_dir"
-                            export __CIBW_VIRTUALENV_PATH__=$venv_dir
+                    docker.call([
+                        'pip', 'wheel',
+                        container_package_dir,
+                        '-w', built_wheel_dir,
+                        '--no-deps',
+                        *get_build_verbosity_extra_flags(options.build_verbosity)
+                    ], env=env)
 
-                            # run the tests in a subshell to keep that `activate`
-                            # script from polluting the env
-                            (
-                                source "$venv_dir/bin/activate"
+                    built_wheel = docker.glob(built_wheel_dir, '*.whl')[0]
 
-                                echo "Running tests using `which python`"
+                    repaired_wheel_dir = temp_dir / 'repaired_wheel'
+                    docker.call(['rm', '-rf', repaired_wheel_dir])
+                    docker.call(['mkdir', '-p', repaired_wheel_dir])
 
-                                if [ ! -z {before_test} ]; then
-                                    sh -c {before_test}
-                                fi
+                    if built_wheel.name.endswith('none-any.whl') or not options.repair_command:
+                        docker.call(['mv', built_wheel, repaired_wheel_dir])
+                    else:
+                        repair_command_prepared = prepare_command(options.repair_command, wheel=built_wheel, dest_dir=repaired_wheel_dir)
+                        docker.call(['sh', '-c', repair_command_prepared], env=env)
 
-                                # Install the wheel we just built
-                                # Note: If auditwheel produced two wheels, it's because the earlier produced wheel
-                                # conforms to multiple manylinux standards. These multiple versions of the wheel are
-                                # functionally the same, differing only in name, wheel metadata, and possibly include
-                                # different external shared libraries. so it doesn't matter which one we run the tests on.
-                                # Let's just pick the first one.
-                                pip install "${{repaired_wheels[0]}}"{test_extras}
+                    repaired_wheels = docker.glob(repaired_wheel_dir, '*.whl')
 
-                                # Install any requirements to run the tests
-                                if [ ! -z "{test_requires}" ]; then
-                                    pip install {test_requires}
-                                fi
+                    if options.test_command:
+                        # set up a virtual environment to install and test from, to make sure
+                        # there are no dependencies that were pulled in at build time.
+                        docker.call(['pip', 'install', 'virtualenv', *dependency_constraint_flags], env=env)
+                        venv_dir = PurePath(docker.call(['mktemp', '-d'], capture_output=True).strip()) / 'venv'
 
-                                # Run the tests from a different directory
-                                pushd $HOME
-                                sh -c {test_command}
-                                popd
-                            )
-                            # exit if tests failed (needed for older bash versions)
-                            if [ $? -ne 0 ]; then
-                              exit 1;
-                            fi
+                        docker.call(['python', '-m', 'virtualenv', '--no-download', venv_dir], env=env)
 
-                            # clean up
-                            rm -rf "$venv_dir"
-                        fi
+                        virtualenv_env = env.copy()
+                        virtualenv_env['PATH'] = f"{venv_dir / 'bin'}:{virtualenv_env['PATH']}"
 
-                        # we're all done here; move it to output
-                        mv "${{repaired_wheels[@]}}" /output
-                        for repaired_wheel in "${{repaired_wheels[@]}}"; do
-                            chown {uid}:{gid} "/output/$(basename "$repaired_wheel")"
-                        done
-                    '''.format(
-                        config_python_bin=config.path + '/bin',
-                        package_dir=container_package_dir,
-                        test_requires=' '.join(options.test_requires),
-                        test_extras=options.test_extras,
-                        test_command=shlex.quote(
-                            prepare_command(options.test_command, project='/project', package=container_package_dir) if options.test_command else ''
-                        ),
-                        before_build=shlex.quote(
-                            prepare_command(options.before_build, project='/project', package=container_package_dir) if options.before_build else ''
-                        ),
-                        build_verbosity_flag=' '.join(get_build_verbosity_extra_flags(options.build_verbosity)),
-                        repair_command=shlex.quote(
-                            prepare_command(options.repair_command, wheel='"$1"', dest_dir='/tmp/repaired_wheels') if options.repair_command else ''
-                        ),
-                        environment_exports='\n'.join(options.environment.as_shell_commands()),
-                        uid=os.getuid(),
-                        gid=os.getgid(),
-                        before_test=shlex.quote(
-                            prepare_command(options.before_test, project='/project', package=container_package_dir) if options.before_test else ''
-                        ),
-                        dependency_install_flags='-c /constraints.txt' if options.dependency_constraints else '',
-                    )
-                )
+                        if options.before_test:
+                            before_test_prepared = prepare_command(options.before_test, project='/project', package=container_package_dir)
+                            docker.call(['sh', '-c', before_test_prepared], env=virtualenv_env)
 
-            # copy the output back into the host
-            call(['docker', 'cp',
-                  container_name + ':/output/.',
-                  os.path.abspath(options.output_dir)])
+                        # Install the wheel we just built
+                        # Note: If auditwheel produced two wheels, it's because the earlier produced wheel
+                        # conforms to multiple manylinux standards. These multiple versions of the wheel are
+                        # functionally the same, differing only in name, wheel metadata, and possibly include
+                        # different external shared libraries. so it doesn't matter which one we run the tests on.
+                        # Let's just pick the first one.
+                        wheel_to_test = repaired_wheels[0]
+                        docker.call(['pip', 'install', str(wheel_to_test) + options.test_extras], env=virtualenv_env)
+
+                        # Install any requirements to run the tests
+                        if options.test_requires:
+                            docker.call(['pip', 'install', *options.test_requires], env=virtualenv_env)
+
+                        # Run the tests from a different directory
+                        test_command_prepared = prepare_command(options.test_command, project='/project', package=container_package_dir)
+                        docker.call(['sh', '-c', test_command_prepared], cwd='/root', env=virtualenv_env)
+
+                        # clean up test environment
+                        docker.call(['rm', '-rf', venv_dir])
+
+                    # move repaired wheels to output
+                    docker.call(['mkdir', '-p', container_output_dir])
+                    docker.call(['mv', *repaired_wheels, container_output_dir])
+
+                # copy the output back into the host
+                docker.copy_out(container_output_dir, options.output_dir)
         except subprocess.CalledProcessError as error:
+            print(f'Command {error.cmd} failed with code {error.returncode}. {error.stdout}')
             troubleshoot(options.package_dir, error)
             exit(1)
-        finally:
-            # Still gets executed, even when 'exit(1)' gets called
-            call(['docker', 'rm', '--force', '-v', container_name])
 
 
-def troubleshoot(package_dir: str, error: Exception) -> None:
+def troubleshoot(package_dir: Path, error: Exception) -> None:
     if (isinstance(error, subprocess.CalledProcessError) and 'exec' in error.cmd):
         # the bash script failed
         print('Checking for common errors...')
-        so_files = []
-        for root, dirs, files in os.walk(package_dir):
-            for name in files:
-                _, ext = os.path.splitext(name)
-                if ext == '.so':
-                    so_files.append(os.path.join(root, name))
+        so_files = list(package_dir.glob('**/*.so'))
 
         if so_files:
             print(textwrap.dedent('''
@@ -305,5 +246,5 @@ def troubleshoot(package_dir: str, error: Exception) -> None:
             '''))
 
             print('  Files detected:')
-            print('\n'.join(['    ' + f for f in so_files]))
+            print('\n'.join([f'    {f}' for f in so_files]))
             print('')

cibuildwheel/macos.py

@@ -4,27 +4,22 @@ import shutil
 import subprocess
 import sys
 import tempfile
-from glob import glob
-
-from typing import Dict, List, Optional, NamedTuple, Union
+from os import PathLike
+from pathlib import Path
+from typing import Dict, List, NamedTuple, Optional, Sequence, Union
 
 from .environment import ParsedEnvironment
-from .util import (
-    BuildOptions,
-    BuildSelector,
-    download,
-    get_build_verbosity_extra_flags,
-    get_pip_script,
-    prepare_command,
-)
+from .util import (BuildOptions, BuildSelector, download,
+                   get_build_verbosity_extra_flags, get_pip_script,
+                   prepare_command)
 
 
-def call(args: Union[str, List[str]], env: Optional[Dict[str, str]] = None, cwd: Optional[str] = None, shell: bool = False) -> int:
+def call(args: Union[str, Sequence[Union[str, PathLike]]], env: Optional[Dict[str, str]] = None, cwd: Optional[str] = None, shell: bool = False) -> int:
     # print the command executing for the logs
     if shell:
         print(f'+ {args}')
     else:
-        print('+ ' + ' '.join(shlex.quote(a) for a in args))
+        print('+ ' + ' '.join(shlex.quote(str(a)) for a in args))
 
     return subprocess.check_call(args, env=env, cwd=cwd, shell=shell)
 
@@ -41,8 +36,8 @@ def get_python_configurations(build_selector: BuildSelector) -> List[PythonConfi
         PythonConfiguration(version='2.7', identifier='cp27-macosx_x86_64', url='https://www.python.org/ftp/python/2.7.18/python-2.7.18-macosx10.9.pkg'),
         PythonConfiguration(version='3.5', identifier='cp35-macosx_x86_64', url='https://www.python.org/ftp/python/3.5.4/python-3.5.4-macosx10.6.pkg'),
         PythonConfiguration(version='3.6', identifier='cp36-macosx_x86_64', url='https://www.python.org/ftp/python/3.6.8/python-3.6.8-macosx10.9.pkg'),
-        PythonConfiguration(version='3.7', identifier='cp37-macosx_x86_64', url='https://www.python.org/ftp/python/3.7.7/python-3.7.7-macosx10.9.pkg'),
-        PythonConfiguration(version='3.8', identifier='cp38-macosx_x86_64', url='https://www.python.org/ftp/python/3.8.3/python-3.8.3-macosx10.9.pkg'),
+        PythonConfiguration(version='3.7', identifier='cp37-macosx_x86_64', url='https://www.python.org/ftp/python/3.7.8/python-3.7.8-macosx10.9.pkg'),
+        PythonConfiguration(version='3.8', identifier='cp38-macosx_x86_64', url='https://www.python.org/ftp/python/3.8.4/python-3.8.4-macosx10.9.pkg'),
         # PyPy
         PythonConfiguration(version='2.7', identifier='pp27-macosx_x86_64', url='https://downloads.python.org/pypy/pypy2.7-v7.3.1-osx64.tar.bz2'),
         PythonConfiguration(version='3.6', identifier='pp36-macosx_x86_64', url='https://downloads.python.org/pypy/pypy3.6-v7.3.1-osx64.tar.bz2'),
@@ -52,41 +47,41 @@ def get_python_configurations(build_selector: BuildSelector) -> List[PythonConfi
     return [c for c in python_configurations if build_selector(c.identifier)]
 
 
-SYMLINKS_DIR = '/tmp/cibw_bin'
+SYMLINKS_DIR = Path('/tmp/cibw_bin')
 
 
-def make_symlinks(installation_bin_path: str, python_executable: str, pip_executable: str) -> None:
-    assert os.path.exists(os.path.join(installation_bin_path, python_executable))
+def make_symlinks(installation_bin_path: Path, python_executable: str, pip_executable: str) -> None:
+    assert (installation_bin_path / python_executable).exists()
 
     # Python bin folders on Mac don't symlink `python3` to `python`, and neither
     # does PyPy for `pypy` or `pypy3`, so we do that so `python` and `pip` always
     # point to the active configuration.
-    if os.path.exists(SYMLINKS_DIR):
+    if SYMLINKS_DIR.exists():
         shutil.rmtree(SYMLINKS_DIR)
-    os.makedirs(SYMLINKS_DIR)
+    SYMLINKS_DIR.mkdir(parents=True)
 
-    os.symlink(os.path.join(installation_bin_path, python_executable), os.path.join(SYMLINKS_DIR, 'python'))
-    os.symlink(os.path.join(installation_bin_path, python_executable + '-config'), os.path.join(SYMLINKS_DIR, 'python-config'))
-    os.symlink(os.path.join(installation_bin_path, pip_executable), os.path.join(SYMLINKS_DIR, 'pip'))
+    (SYMLINKS_DIR / 'python').symlink_to(installation_bin_path / python_executable)
+    (SYMLINKS_DIR / 'python-config').symlink_to(installation_bin_path / (python_executable + '-config'))
+    (SYMLINKS_DIR / 'pip').symlink_to(installation_bin_path / pip_executable)
 
 
-def install_cpython(version: str, url: str) -> str:
+def install_cpython(version: str, url: str) -> Path:
     installed_system_packages = subprocess.check_output(['pkgutil', '--pkgs'], universal_newlines=True).splitlines()
 
     # if this version of python isn't installed, get it from python.org and install
     python_package_identifier = f'org.python.Python.PythonFramework-{version}'
     if python_package_identifier not in installed_system_packages:
         # download the pkg
-        download(url, '/tmp/Python.pkg')
+        download(url, Path('/tmp/Python.pkg'))
         # install
         call(['sudo', 'installer', '-pkg', '/tmp/Python.pkg', '-target', '/'])
         # patch open ssl
         if version == '3.5':
             open_ssl_patch_url = f'https://github.com/mayeut/patch-macos-python-openssl/releases/download/v1.0.2u/patch-macos-python-{version}-openssl-v1.0.2u.tar.gz'
-            download(open_ssl_patch_url, '/tmp/python-patch.tar.gz')
+            download(open_ssl_patch_url, Path('/tmp/python-patch.tar.gz'))
             call(['sudo', 'tar', '-C', f'/Library/Frameworks/Python.framework/Versions/{version}/', '-xmf', '/tmp/python-patch.tar.gz'])
 
-    installation_bin_path = f'/Library/Frameworks/Python.framework/Versions/{version}/bin'
+    installation_bin_path = Path(f'/Library/Frameworks/Python.framework/Versions/{version}/bin')
     python_executable = 'python3' if version[0] == '3' else 'python'
     pip_executable = 'pip3' if version[0] == '3' else 'pip'
     make_symlinks(installation_bin_path, python_executable, pip_executable)
@@ -94,16 +89,18 @@ def install_cpython(version: str, url: str) -> str:
     return installation_bin_path
 
 
-def install_pypy(version: str, url: str) -> str:
+def install_pypy(version: str, url: str) -> Path:
     pypy_tar_bz2 = url.rsplit('/', 1)[-1]
-    assert pypy_tar_bz2.endswith(".tar.bz2")
-    pypy_base_filename = os.path.splitext(os.path.splitext(pypy_tar_bz2)[0])[0]
-    installation_path = os.path.join('/tmp', pypy_base_filename)
-    if not os.path.exists(installation_path):
-        download(url, os.path.join("/tmp", pypy_tar_bz2))
-        call(['tar', '-C', '/tmp', '-xf', os.path.join("/tmp", pypy_tar_bz2)])
+    extension = ".tar.bz2"
+    assert pypy_tar_bz2.endswith(extension)
+    pypy_base_filename = pypy_tar_bz2[:-len(extension)]
+    installation_path = Path('/tmp') / pypy_base_filename
+    if not installation_path.exists():
+        downloaded_tar_bz2 = Path("/tmp") / pypy_tar_bz2
+        download(url, downloaded_tar_bz2)
+        call(['tar', '-C', '/tmp', '-xf', downloaded_tar_bz2])
 
-    installation_bin_path = os.path.join(installation_path, 'bin')
+    installation_bin_path = installation_path / 'bin'
     python_executable = 'pypy3' if version[0] == '3' else 'pypy'
     pip_executable = 'pip3' if version[0] == '3' else 'pip'
     make_symlinks(installation_bin_path, python_executable, pip_executable)
@@ -111,7 +108,9 @@ def install_pypy(version: str, url: str) -> str:
     return installation_bin_path
 
 
-def setup_python(python_configuration: PythonConfiguration, dependency_constraint_flags: List[str], environment: ParsedEnvironment) -> Dict[str, str]:
+def setup_python(python_configuration: PythonConfiguration,
+                 dependency_constraint_flags: Sequence[Union[str, PathLike]],
+                 environment: ParsedEnvironment) -> Dict[str, str]:
     if python_configuration.identifier.startswith('cp'):
         installation_bin_path = install_cpython(python_configuration.version, python_configuration.url)
     elif python_configuration.identifier.startswith('pp'):
@@ -121,8 +120,8 @@ def setup_python(python_configuration: PythonConfiguration, dependency_constrain
 
     env = os.environ.copy()
     env['PATH'] = os.pathsep.join([
-        SYMLINKS_DIR,
-        installation_bin_path,
+        str(SYMLINKS_DIR),
+        str(installation_bin_path),
         env['PATH'],
     ])
 
@@ -144,15 +143,15 @@ def setup_python(python_configuration: PythonConfiguration, dependency_constrain
         exit(1)
 
     # install pip & wheel
-    call(['python', get_pip_script] + dependency_constraint_flags, env=env, cwd="/tmp")
-    assert os.path.exists(os.path.join(installation_bin_path, 'pip'))
+    call(['python', get_pip_script, *dependency_constraint_flags], env=env, cwd="/tmp")
+    assert (installation_bin_path / 'pip').exists()
     call(['which', 'pip'], env=env)
     call(['pip', '--version'], env=env)
     which_pip = subprocess.check_output(['which', 'pip'], env=env, universal_newlines=True).strip()
     if which_pip != '/tmp/cibw_bin/pip':
         print("cibuildwheel: pip available on PATH doesn't match our installed instance. If you have modified PATH, ensure that you don't overwrite cibuildwheel's entry or insert pip above it.", file=sys.stderr)
         exit(1)
-    call(['pip', 'install', '--upgrade', 'setuptools', 'wheel', 'delocate'] + dependency_constraint_flags, env=env)
+    call(['pip', 'install', '--upgrade', 'setuptools', 'wheel', 'delocate', *dependency_constraint_flags], env=env)
 
     # Set MACOSX_DEPLOYMENT_TARGET to 10.9, if the user didn't set it.
     # CPython 3.5 defaults to 10.6, and pypy defaults to 10.7, causing
@@ -170,14 +169,19 @@ def setup_python(python_configuration: PythonConfiguration, dependency_constrain
 
 
 def build(options: BuildOptions) -> None:
-    temp_dir = tempfile.mkdtemp(prefix='cibuildwheel')
-    built_wheel_dir = os.path.join(temp_dir, 'built_wheel')
-    repaired_wheel_dir = os.path.join(temp_dir, 'repaired_wheel')
+    temp_dir = Path(tempfile.mkdtemp(prefix='cibuildwheel'))
+    built_wheel_dir = temp_dir / 'built_wheel'
+    repaired_wheel_dir = temp_dir / 'repaired_wheel'
+
+    if options.before_all:
+        env = options.environment.as_dictionary(prev_environment=os.environ)
+        before_all_prepared = prepare_command(options.before_all, project='.', package=options.package_dir)
+        call([before_all_prepared], shell=True, env=env)
 
     python_configurations = get_python_configurations(options.build_selector)
 
     for config in python_configurations:
-        dependency_constraint_flags = []
+        dependency_constraint_flags: Sequence[Union[str, PathLike]] = []
         if options.dependency_constraints:
             dependency_constraint_flags = [
                 '-c', options.dependency_constraints.get_for_python_version(config.version)
@@ -191,29 +195,39 @@ def build(options: BuildOptions) -> None:
             call(before_build_prepared, env=env, shell=True)
 
         # build the wheel
-        if os.path.exists(built_wheel_dir):
+        if built_wheel_dir.exists():
             shutil.rmtree(built_wheel_dir)
-        os.makedirs(built_wheel_dir)
-        call(['pip', 'wheel', options.package_dir, '-w', built_wheel_dir, '--no-deps'] + get_build_verbosity_extra_flags(options.build_verbosity), env=env)
-        built_wheel = glob(os.path.join(built_wheel_dir, '*.whl'))[0]
+        built_wheel_dir.mkdir(parents=True)
+
+        # Path.resolve() is needed. Without it pip wheel may try to fetch package from pypi.org
+        # see https://github.com/joerick/cibuildwheel/pull/369
+        call([
+            'pip', 'wheel',
+            options.package_dir.resolve(),
+            '-w', built_wheel_dir,
+            '--no-deps',
+            *get_build_verbosity_extra_flags(options.build_verbosity)
+        ], env=env)
+
+        built_wheel = next(built_wheel_dir.glob('*.whl'))
 
         # repair the wheel
-        if os.path.exists(repaired_wheel_dir):
+        if repaired_wheel_dir.exists():
             shutil.rmtree(repaired_wheel_dir)
-        os.makedirs(repaired_wheel_dir)
-        if built_wheel.endswith('none-any.whl') or not options.repair_command:
+        repaired_wheel_dir.mkdir(parents=True)
+        if built_wheel.name.endswith('none-any.whl') or not options.repair_command:
             # pure Python wheel or empty repair command
-            shutil.move(built_wheel, repaired_wheel_dir)
+            shutil.move(str(built_wheel), repaired_wheel_dir)
         else:
             repair_command_prepared = prepare_command(options.repair_command, wheel=built_wheel, dest_dir=repaired_wheel_dir)
             call(repair_command_prepared, env=env, shell=True)
-        repaired_wheel = glob(os.path.join(repaired_wheel_dir, '*.whl'))[0]
+        repaired_wheel = next(repaired_wheel_dir.glob('*.whl'))
 
         if options.test_command:
             # set up a virtual environment to install and test from, to make sure
             # there are no dependencies that were pulled in at build time.
-            call(['pip', 'install', 'virtualenv'] + dependency_constraint_flags, env=env)
-            venv_dir = tempfile.mkdtemp()
+            call(['pip', 'install', 'virtualenv', *dependency_constraint_flags], env=env)
+            venv_dir = Path(tempfile.mkdtemp())
 
             # Use --no-download to ensure determinism by using seed libraries
             # built into virtualenv
@@ -221,10 +235,9 @@ def build(options: BuildOptions) -> None:
 
             virtualenv_env = env.copy()
             virtualenv_env['PATH'] = os.pathsep.join([
-                os.path.join(venv_dir, 'bin'),
+                str(venv_dir / 'bin'),
                 virtualenv_env['PATH'],
             ])
-            virtualenv_env["__CIBW_VIRTUALENV_PATH__"] = venv_dir
 
             # check that we are using the Python from the virtual environment
             call(['which', 'python'], env=virtualenv_env)
@@ -234,7 +247,7 @@ def build(options: BuildOptions) -> None:
                 call(before_test_prepared, env=virtualenv_env, shell=True)
 
             # install the wheel
-            call(['pip', 'install', repaired_wheel + options.test_extras], env=virtualenv_env)
+            call(['pip', 'install', str(repaired_wheel) + options.test_extras], env=virtualenv_env)
 
             # test the wheel
             if options.test_requires:
@@ -245,8 +258,8 @@ def build(options: BuildOptions) -> None:
             # and not the repo code)
             test_command_prepared = prepare_command(
                 options.test_command,
-                project=os.path.abspath('.'),
-                package=os.path.abspath(options.package_dir)
+                project=Path('.').resolve(),
+                package=options.package_dir.resolve()
             )
             call(test_command_prepared, cwd=os.environ['HOME'], env=virtualenv_env, shell=True)
 
@@ -254,5 +267,4 @@ def build(options: BuildOptions) -> None:
             shutil.rmtree(venv_dir)
 
         # we're all done here; move it to output (overwrite existing)
-        dst = os.path.join(options.output_dir, os.path.basename(repaired_wheel))
-        shutil.move(repaired_wheel, dst)
+        shutil.move(str(repaired_wheel), options.output_dir)

cibuildwheel/util.py

@@ -1,14 +1,15 @@
 import os
 import urllib.request
 from fnmatch import fnmatch
+from pathlib import Path
 from time import sleep
 
-from typing import Dict, List, NamedTuple, Optional
+from typing import Dict, List, NamedTuple, Optional, Union
 
 from .environment import ParsedEnvironment
 
 
-def prepare_command(command: str, **kwargs: str) -> str:
+def prepare_command(command: str, **kwargs: Union[str, os.PathLike]) -> str:
     '''
     Preprocesses a command by expanding variables like {python}.
 
@@ -58,11 +59,11 @@ class Unbuffered:
         return getattr(self.stream, attr)
 
 
-def download(url: str, dest: str) -> None:
-    print('+ Download ' + url + ' to ' + dest)
-    dest_dir = os.path.dirname(dest)
-    if not os.path.exists(dest_dir):
-        os.makedirs(dest_dir)
+def download(url: str, dest: Path) -> None:
+    print(f'+ Download {url} to {dest}')
+    dest_dir = dest.parent
+    if not dest_dir.exists():
+        dest_dir.mkdir(parents=True)
 
     repeat_num = 3
     for i in range(repeat_num):
@@ -76,52 +77,52 @@ def download(url: str, dest: str) -> None:
         break
 
     try:
-        with open(dest, 'wb') as file:
-            file.write(response.read())
+        dest.write_bytes(response.read())
     finally:
         response.close()
 
 
 class DependencyConstraints:
-    def __init__(self, base_file_path: str):
-        assert os.path.exists(base_file_path)
-        self.base_file_path = os.path.abspath(base_file_path)
+    def __init__(self, base_file_path: Path):
+        assert base_file_path.exists()
+        self.base_file_path = base_file_path.resolve()
 
     @staticmethod
     def with_defaults() -> 'DependencyConstraints':
         return DependencyConstraints(
-            base_file_path=os.path.join(os.path.dirname(__file__), 'resources', 'constraints.txt')
+            base_file_path=resources_dir / 'constraints.txt'
         )
 
-    def get_for_python_version(self, version: str) -> str:
+    def get_for_python_version(self, version: str) -> Path:
         version_parts = version.split('.')
 
         # try to find a version-specific dependency file e.g. if
         # ./constraints.txt is the base, look for ./constraints-python27.txt
-        base, ext = os.path.splitext(self.base_file_path)
-        specific = base + f'-python{version_parts[0]}{version_parts[1]}'
-        specific_file_path = specific + ext
-        if os.path.exists(specific_file_path):
+        specific_stem = self.base_file_path.stem + f'-python{version_parts[0]}{version_parts[1]}'
+        specific_name = specific_stem + self.base_file_path.suffix
+        specific_file_path = self.base_file_path.with_name(specific_name)
+        if specific_file_path.exists():
             return specific_file_path
         else:
             return self.base_file_path
 
 
 class BuildOptions(NamedTuple):
-    package_dir: str
-    output_dir: str
+    package_dir: Path
+    output_dir: Path
+    build_selector: BuildSelector
+    environment: ParsedEnvironment
+    before_all: str
+    before_build: Optional[str]
+    repair_command: str
+    manylinux_images: Optional[Dict[str, str]]
+    dependency_constraints: Optional[DependencyConstraints]
     test_command: Optional[str]
+    before_test: Optional[str]
     test_requires: List[str]
     test_extras: str
-    before_build: Optional[str]
     build_verbosity: int
-    build_selector: BuildSelector
-    repair_command: str
-    environment: ParsedEnvironment
-    before_test: str
-    dependency_constraints: Optional[DependencyConstraints]
-    manylinux_images: Optional[Dict[str, str]]
 
 
-resources_dir = os.path.abspath(os.path.join(os.path.dirname(__file__), 'resources'))
-get_pip_script = os.path.join(resources_dir, 'get-pip.py')
+resources_dir = Path(__file__).resolve().parent / 'resources'
+get_pip_script = resources_dir / 'get-pip.py'

cibuildwheel/windows.py

@@ -3,29 +3,32 @@ import shutil
 import subprocess
 import sys
 import tempfile
-from glob import glob
+from os import PathLike
+from pathlib import Path
+from typing import Dict, List, NamedTuple, Optional, Sequence, Union
 from zipfile import ZipFile
-
-from typing import Dict, List, Optional, NamedTuple
+import toml
 
 from .environment import ParsedEnvironment
-from .util import (
-    BuildOptions,
-    BuildSelector,
-    download,
-    get_build_verbosity_extra_flags,
-    get_pip_script,
-    prepare_command,
-)
+from .util import (BuildOptions, BuildSelector, download,
+                   get_build_verbosity_extra_flags, get_pip_script,
+                   prepare_command)
 
-
-IS_RUNNING_ON_AZURE = os.path.exists('C:\\hostedtoolcache')
+IS_RUNNING_ON_AZURE = Path('C:\\hostedtoolcache').exists()
 IS_RUNNING_ON_TRAVIS = os.environ.get('TRAVIS_OS_NAME') == 'windows'
 
 
-def shell(args: List[str], env: Optional[Dict[str, str]] = None, cwd: Optional[str] = None) -> int:
-    print('+ ' + ' '.join(args))
-    return subprocess.check_call(' '.join(args), env=env, cwd=cwd, shell=True)
+def call(args: Sequence[Union[str, PathLike]], env: Optional[Dict[str, str]] = None,
+         cwd: Optional[str] = None) -> None:
+    print('+ ' + ' '.join(str(a) for a in args))
+    # we use shell=True here, even though we don't need a shell due to a bug
+    # https://bugs.python.org/issue8557
+    subprocess.check_call([str(a) for a in args], env=env, cwd=cwd, shell=True)
+
+
+def shell(command: str, env: Optional[Dict[str, str]] = None, cwd: Optional[str] = None) -> None:
+    print(f'+ {command}')
+    subprocess.check_call(command, env=env, cwd=cwd, shell=True)
 
 
 def get_nuget_args(version: str, arch: str) -> List[str]:
@@ -51,10 +54,10 @@ def get_python_configurations(build_selector: BuildSelector) -> List[PythonConfi
         PythonConfiguration(version='3.5.4', arch='64', identifier='cp35-win_amd64', url=None),
         PythonConfiguration(version='3.6.8', arch='32', identifier='cp36-win32', url=None),
         PythonConfiguration(version='3.6.8', arch='64', identifier='cp36-win_amd64', url=None),
-        PythonConfiguration(version='3.7.7', arch='32', identifier='cp37-win32', url=None),
-        PythonConfiguration(version='3.7.7', arch='64', identifier='cp37-win_amd64', url=None),
-        PythonConfiguration(version='3.8.3', arch='32', identifier='cp38-win32', url=None),
-        PythonConfiguration(version='3.8.3', arch='64', identifier='cp38-win_amd64', url=None),
+        PythonConfiguration(version='3.7.8', arch='32', identifier='cp37-win32', url=None),
+        PythonConfiguration(version='3.7.8', arch='64', identifier='cp37-win_amd64', url=None),
+        PythonConfiguration(version='3.8.4', arch='32', identifier='cp38-win32', url=None),
+        PythonConfiguration(version='3.8.4', arch='64', identifier='cp38-win_amd64', url=None),
         # PyPy
         PythonConfiguration(version='2.7', arch='32', identifier='pp27-win32', url='https://downloads.python.org/pypy/pypy2.7-v7.3.1-win32.zip'),
         PythonConfiguration(version='3.6', arch='32', identifier='pp36-win32', url='https://downloads.python.org/pypy/pypy3.6-v7.3.1-win32.zip'),
@@ -71,36 +74,38 @@ def get_python_configurations(build_selector: BuildSelector) -> List[PythonConfi
     return python_configurations
 
 
-def extract_zip(zip_src: str, dest: str) -> None:
+def extract_zip(zip_src: Path, dest: Path) -> None:
     with ZipFile(zip_src) as zip:
         zip.extractall(dest)
 
 
-def install_cpython(version: str, arch: str, nuget: str) -> str:
+def install_cpython(version: str, arch: str, nuget: Path) -> Path:
     nuget_args = get_nuget_args(version, arch)
-    installation_path = os.path.join(nuget_args[-1], nuget_args[0] + '.' + version, 'tools')
-    shell([nuget, 'install'] + nuget_args)
+    installation_path = Path(nuget_args[-1]) / (nuget_args[0] + '.' + version) / 'tools'
+    call([nuget, 'install', *nuget_args])
     return installation_path
 
 
-def install_pypy(version: str, arch: str, url: str) -> str:
+def install_pypy(version: str, arch: str, url: str) -> Path:
     assert arch == '32'
     # Inside the PyPy zip file is a directory with the same name
     zip_filename = url.rsplit('/', 1)[-1]
-    installation_path = os.path.join('C:\\cibw', os.path.splitext(zip_filename)[0])
-    if not os.path.exists(installation_path):
-        pypy_zip = os.path.join('C:\\cibw', zip_filename)
+    extension = ".zip"
+    assert zip_filename.endswith(extension)
+    installation_path = Path('C:\\cibw') / zip_filename[:-len(extension)]
+    if not installation_path.exists():
+        pypy_zip = Path('C:\\cibw') / zip_filename
         download(url, pypy_zip)
         # Extract to the parent directory because the zip file still contains a directory
-        extract_zip(pypy_zip, os.path.dirname(installation_path))
+        extract_zip(pypy_zip, installation_path.parent)
         pypy_exe = 'pypy3.exe' if version[0] == '3' else 'pypy.exe'
-        shell(['mklink', os.path.join(installation_path, 'python.exe'), os.path.join(installation_path, pypy_exe)])
+        (installation_path / 'python.exe').symlink_to(installation_path / pypy_exe)
     return installation_path
 
 
-def setup_python(python_configuration: PythonConfiguration, dependency_constraint_flags: List[str], environment: ParsedEnvironment) -> Dict[str, str]:
-    nuget = 'C:\\cibw\\nuget.exe'
-    if not os.path.exists(nuget):
+def setup_python(python_configuration: PythonConfiguration, dependency_constraint_flags: Sequence[Union[str, PathLike]], environment: ParsedEnvironment) -> Dict[str, str]:
+    nuget = Path('C:\\cibw\\nuget.exe')
+    if not nuget.exists():
         download('https://dist.nuget.org/win-x86-commandline/latest/nuget.exe', nuget)
 
     if python_configuration.identifier.startswith('cp'):
@@ -111,58 +116,88 @@ def setup_python(python_configuration: PythonConfiguration, dependency_constrain
     else:
         raise ValueError("Unknown Python implementation")
 
-    assert os.path.exists(os.path.join(installation_path, 'python.exe'))
+    assert (installation_path / 'python.exe').exists()
 
     # set up PATH and environment variables for run_with_env
     env = os.environ.copy()
     env['PYTHON_VERSION'] = python_configuration.version
     env['PYTHON_ARCH'] = python_configuration.arch
     env['PATH'] = os.pathsep.join([
-        installation_path,
-        os.path.join(installation_path, 'Scripts'),
+        str(installation_path),
+        str(installation_path / 'Scripts'),
         env['PATH']
     ])
     # update env with results from CIBW_ENVIRONMENT
     env = environment.as_dictionary(prev_environment=env)
 
     # for the logs - check we're running the right version of python
-    shell(['where', 'python'], env=env)
-    shell(['python', '--version'], env=env)
-    shell(['python', '-c', '"import struct; print(struct.calcsize(\'P\') * 8)"'], env=env)
+    call(['where', 'python'], env=env)
+    call(['python', '--version'], env=env)
+    call(['python', '-c', '"import struct; print(struct.calcsize(\'P\') * 8)"'], env=env)
     where_python = subprocess.check_output(['where', 'python'], env=env, universal_newlines=True).splitlines()[0].strip()
-    if where_python != os.path.join(installation_path, 'python.exe'):
+    if where_python != str(installation_path / 'python.exe'):
         print("cibuildwheel: python available on PATH doesn't match our installed instance. If you have modified PATH, ensure that you don't overwrite cibuildwheel's entry or insert python above it.", file=sys.stderr)
         exit(1)
 
     # make sure pip is installed
-    if not os.path.exists(os.path.join(installation_path, 'Scripts', 'pip.exe')):
-        shell(['python', get_pip_script] + dependency_constraint_flags, env=env, cwd="C:\\cibw")
-    assert os.path.exists(os.path.join(installation_path, 'Scripts', 'pip.exe'))
+    if not (installation_path / 'Scripts' / 'pip.exe').exists():
+        call(['python', get_pip_script, *dependency_constraint_flags], env=env, cwd="C:\\cibw")
+    assert (installation_path / 'Scripts' / 'pip.exe').exists()
     where_pip = subprocess.check_output(['where', 'pip'], env=env, universal_newlines=True).splitlines()[0].strip()
-    if where_pip.strip() != os.path.join(installation_path, 'Scripts', 'pip.exe'):
+    if where_pip.strip() != str(installation_path / 'Scripts' / 'pip.exe'):
         print("cibuildwheel: pip available on PATH doesn't match our installed instance. If you have modified PATH, ensure that you don't overwrite cibuildwheel's entry or insert pip above it.", file=sys.stderr)
         exit(1)
 
     # prepare the Python environment
-    shell(['python', '-m', 'pip', 'install', '--upgrade', 'pip'] + dependency_constraint_flags, env=env)
-    shell(['pip', '--version'], env=env)
-    shell(['pip', 'install', '--upgrade', 'setuptools', 'wheel'] + dependency_constraint_flags, env=env)
+    call(['python', '-m', 'pip', 'install', '--upgrade', 'pip', *dependency_constraint_flags], env=env)
+    call(['pip', '--version'], env=env)
+    call(['pip', 'install', '--upgrade', 'setuptools', 'wheel', *dependency_constraint_flags], env=env)
 
     return env
 
 
+def pep_518_cp35_workaround(package_dir: Path, env: Dict[str, str]) -> None:
+    """
+    Python 3.5 PEP 518 hack (see https://github.com/pypa/pip/issues/8392#issuecomment-639563494)
+    Basically, nuget's Python is an embedded Python distribution, which is not supported by pip.
+    Before version 3.6, there was no way to disable the "embedded" behavior, including the ignoring
+    of environment variables, including the ones pip uses to setup PEP 518 builds.
+
+    The fix here is as suggested in that issue; we manually setup the PEP 518 requirements. Since we
+    are in a fresh environment (except for pinned cibuildweel dependencies), the build is already
+    mostly "isolated".
+    """
+
+    pyproject_path = package_dir / 'pyproject.toml'
+
+    if pyproject_path.exists():
+        data = toml.load(pyproject_path)
+        requirements = (
+            data['build-system'].get('requires', [])
+            if 'build-system' in data
+            else []
+        )
+        if requirements:
+            shell(['pip', 'install'] + requirements, env=env)
+
+
 def build(options: BuildOptions) -> None:
-    temp_dir = tempfile.mkdtemp(prefix='cibuildwheel')
-    built_wheel_dir = os.path.join(temp_dir, 'built_wheel')
-    repaired_wheel_dir = os.path.join(temp_dir, 'repaired_wheel')
+    temp_dir = Path(tempfile.mkdtemp(prefix='cibuildwheel'))
+    built_wheel_dir = temp_dir / 'built_wheel'
+    repaired_wheel_dir = temp_dir / 'repaired_wheel'
 
     # install nuget as best way to provide python
-    nuget = 'C:\\cibw\\nuget.exe'
+    nuget = Path('C:\\cibw\\nuget.exe')
     download('https://dist.nuget.org/win-x86-commandline/latest/nuget.exe', nuget)
 
+    if options.before_all:
+        env = options.environment.as_dictionary(prev_environment=os.environ)
+        before_all_prepared = prepare_command(options.before_all, project='.', package=options.package_dir)
+        shell(before_all_prepared, env=env)
+
     python_configurations = get_python_configurations(options.build_selector)
     for config in python_configurations:
-        dependency_constraint_flags = []
+        dependency_constraint_flags: Sequence[Union[str, PathLike]] = []
         if options.dependency_constraints:
             dependency_constraint_flags = [
                 '-c', options.dependency_constraints.get_for_python_version(config.version)
@@ -174,48 +209,59 @@ def build(options: BuildOptions) -> None:
         # run the before_build command
         if options.before_build:
             before_build_prepared = prepare_command(options.before_build, project='.', package=options.package_dir)
-            shell([before_build_prepared], env=env)
+            shell(before_build_prepared, env=env)
+
+        # activate the PEP 518 patch if on Windows Python 3.5
+        # (will only have an effect if PEP 517 builds are used):
+        if config.version.startswith('3.5'):
+            pep_518_cp35_workaround(options.package_dir, env)
 
         # build the wheel
-        if os.path.exists(built_wheel_dir):
+        if built_wheel_dir.exists():
             shutil.rmtree(built_wheel_dir)
-        os.makedirs(built_wheel_dir)
-        shell(['pip', 'wheel', options.package_dir, '-w', built_wheel_dir, '--no-deps'] + get_build_verbosity_extra_flags(options.build_verbosity), env=env)
-        built_wheel = glob(os.path.join(built_wheel_dir, '*.whl'))[0]
+        built_wheel_dir.mkdir(parents=True)
+        # Path.resolve() is needed. Without it pip wheel may try to fetch package from pypi.org
+        # see https://github.com/joerick/cibuildwheel/pull/369
+        call([
+            'pip', 'wheel',
+            options.package_dir.resolve(),
+            '-w', built_wheel_dir,
+            '--no-deps',
+            *get_build_verbosity_extra_flags(options.build_verbosity)
+        ], env=env)
+
+        built_wheel = next(built_wheel_dir.glob('*.whl'))
 
         # repair the wheel
-        if os.path.exists(repaired_wheel_dir):
+        if repaired_wheel_dir.exists():
             shutil.rmtree(repaired_wheel_dir)
-        os.makedirs(repaired_wheel_dir)
-        if built_wheel.endswith('none-any.whl') or not options.repair_command:
+        repaired_wheel_dir.mkdir(parents=True)
+        if built_wheel.name.endswith('none-any.whl') or not options.repair_command:
             # pure Python wheel or empty repair command
-            shutil.move(built_wheel, repaired_wheel_dir)
+            shutil.move(str(built_wheel), repaired_wheel_dir)
         else:
             repair_command_prepared = prepare_command(options.repair_command, wheel=built_wheel, dest_dir=repaired_wheel_dir)
-            shell([repair_command_prepared], env=env)
-        repaired_wheel = glob(os.path.join(repaired_wheel_dir, '*.whl'))[0]
+            shell(repair_command_prepared, env=env)
+        repaired_wheel = next(repaired_wheel_dir.glob('*.whl'))
 
         if options.test_command:
             # set up a virtual environment to install and test from, to make sure
             # there are no dependencies that were pulled in at build time.
-            shell(['pip', 'install', 'virtualenv'] + dependency_constraint_flags, env=env)
-            venv_dir = tempfile.mkdtemp()
+            call(['pip', 'install', 'virtualenv', *dependency_constraint_flags], env=env)
+            venv_dir = Path(tempfile.mkdtemp())
 
             # Use --no-download to ensure determinism by using seed libraries
             # built into virtualenv
-            shell(['python', '-m', 'virtualenv', '--no-download', venv_dir], env=env)
+            call(['python', '-m', 'virtualenv', '--no-download', venv_dir], env=env)
 
             virtualenv_env = env.copy()
-
-            venv_script_path = os.path.join(venv_dir, 'Scripts')
             virtualenv_env['PATH'] = os.pathsep.join([
-                venv_script_path,
+                str(venv_dir / 'Scripts'),
                 virtualenv_env['PATH'],
             ])
-            virtualenv_env["__CIBW_VIRTUALENV_PATH__"] = venv_dir
 
             # check that we are using the Python from the virtual environment
-            shell(['which', 'python'], env=virtualenv_env)
+            call(['which', 'python'], env=virtualenv_env)
 
             if options.before_test:
                 before_test_prepared = prepare_command(
@@ -223,30 +269,27 @@ def build(options: BuildOptions) -> None:
                     project='.',
                     package=options.package_dir
                 )
-                shell([before_test_prepared], env=virtualenv_env)
+                shell(before_test_prepared, env=virtualenv_env)
 
             # install the wheel
-            shell(['pip', 'install', repaired_wheel + options.test_extras], env=virtualenv_env)
+            call(['pip', 'install', str(repaired_wheel) + options.test_extras], env=virtualenv_env)
 
             # test the wheel
             if options.test_requires:
-                shell(['pip', 'install'] + options.test_requires, env=virtualenv_env)
+                call(['pip', 'install'] + options.test_requires, env=virtualenv_env)
 
             # run the tests from c:\, with an absolute path in the command
             # (this ensures that Python runs the tests against the installed wheel
             # and not the repo code)
             test_command_prepared = prepare_command(
                 options.test_command,
-                project=os.path.abspath('.'),
-                package=os.path.abspath(options.package_dir)
+                project=Path('.').resolve(),
+                package=options.package_dir.resolve()
             )
-            shell([test_command_prepared], cwd='c:\\', env=virtualenv_env)
+            shell(test_command_prepared, cwd='c:\\', env=virtualenv_env)
 
             # clean up
             shutil.rmtree(venv_dir)
 
         # we're all done here; move it to output (remove if already exists)
-        dst = os.path.join(options.output_dir, os.path.basename(repaired_wheel))
-        if os.path.isfile(dst):
-            os.remove(dst)
-        shutil.move(repaired_wheel, dst)
+        shutil.move(str(repaired_wheel), options.output_dir)

docs/cpp_standards.md

@@ -39,5 +39,31 @@ Forcing `distutils` or `setuptools` to use a more recent version of MSVC that su
 1. Set the environment variables `DISTUTILS_USE_SDK=1` and `MSSdk=1`. These two environment variables will tell `distutils`/`setuptools` to not search and set up a build environment that uses Visual C++ for Python 2.7 (aka. MSVC 9).
 2. Set up the build Visual Studio build environment you want to use, making sure that e.g. `PATH` contains `cl`, `link`, etc.
     - Usually, this can be done through `vcvarsall.bat x86` or `vcvarsall.bat x64`. The exact location of this file depends on the installation, but the default path for VS 2019 Community (e.g. used in AppVeyor's `Visual Studio 2019` image) is `C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Auxiliary\Build\vcvarsall.bat`. **Note**: `vcvarsall.bat` changes the environment variables, so this cannot be run in a subprocess/subshell and consequently running `vsvarsall.bat` in `CIBW_BEFORE_BUILD` does not have any effect.
-    - In Azure Pipelines, [a `VSBuild` task is available](https://docs.microsoft.com/en-us/azure/devops/pipelines/tasks/build/visual-studio-build) and GitHub Actions has [an action `microsoft/setup-msbuild`](https://github.com/microsoft/setup-msbuild) that help setting up the Visual Studio environment.
-3. Next, call `cibuildwheel`. Unfortunately, MSVC has separate toolchains for compiling 32-bit and 64-bit, so you will need to run `cibuildwheel` twice: once with `CIBW_BUILD=*-win32` after setting up the `x86` build environment, and once with `CIBW_BUILD=*-win_amd64` in a `x64` enviroment (see previous step).
+    - In Azure Pipelines, [a `VSBuild` task is available](https://docs.microsoft.com/en-us/azure/devops/pipelines/tasks/build/visual-studio-build)
+    - In GitHub Actions, the default shell is powershell, so you'll need to use `shell: cmd` to source a `.bat` file, and the directory is `"C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\VC\Auxiliary\Build\vcvarsall.bat"`. Or you can use an action, such as the [`ilammy/msvc-dev-cmd@v1`](https://github.com/ilammy/msvc-dev-cmd) action to setup the environment (see example below).
+3. Next, call `cibuildwheel`. Unfortunately, MSVC has separate toolchains for compiling 32-bit and 64-bit, so you will need to run `cibuildwheel` twice: once with `CIBW_BUILD=*-win32` after setting up the `x86` build environment, and once with `CIBW_BUILD=*-win_amd64` in a `x64` environment (see previous step).
+
+
+**GitHub Action example with ilammy/msvc-dev-cmd**:
+
+```yaml
+  - uses: ilammy/msvc-dev-cmd@v1
+
+  - name: Build 64-bit wheel
+    run: python -m cibuildwheel --output-dir wheelhouse
+    env:
+      CIBW_BUILD: cp27-win_amd64
+      DISTUTILS_USE_SDK: 1
+      MSSdk: 1
+
+  - uses: ilammy/msvc-dev-cmd@v1
+    with:
+      arch: x86
+
+  - name: Build 32-bit wheel
+    run: python -m cibuildwheel --output-dir wheelhouse
+    env:
+      CIBW_BUILD: cp27-win32
+      DISTUTILS_USE_SDK: 1
+      MSSdk: 1
+```

docs/deliver-to-pypi.md

@@ -33,4 +33,4 @@ Obviously, manual steps are for chumps, so we can automate this a little by usin
 
 If you don't need much control over the release of a package, you can set up cibuildwheel to deliver the wheels straight to PyPI. This doesn't require anycloud storage to work - you just need to bump the version and tag it.
 
-Check out [this example repo](https://github.com/joerick/cibuildwheel-autopypi-example) for instructions on how to set this up.
+[`examples/travis-ci-deploy.yml`](https://github.com/joerick/cibuildwheel/blob/master/examples/travis-ci-deploy.yml) and [`examples/github-deploy.yml`](https://github.com/joerick/cibuildwheel/blob/master/examples/github-deploy.yml) are example configurations that automatocially upload wheels to PyPI. Also check out [this example repo](https://github.com/joerick/cibuildwheel-autopypi-example) for more detailed instructions on how to set this up.

docs/extra.js

@@ -2,4 +2,3 @@
 $('.rst-content pre')
     .prev('blockquote')
     .addClass('code-block-filename');
-

docs/mkdocs_include_markdown_plugin/mkdocs_include_markdown_plugin/plugin.py

@@ -1,7 +1,6 @@
 import cgi
-import io
-import os
 import re
+from pathlib import Path
 
 import mkdocs
 
@@ -41,13 +40,12 @@ class ImportMarkdownPlugin(mkdocs.plugins.BasePlugin):
         def found_include_tag(match):
             filename = match.group('filename')
 
-            file_path_abs = os.path.join(os.path.dirname(page_src_path), filename)
+            file_path_abs = Path(page_src_path).parent / filename
 
-            if not os.path.exists(file_path_abs):
+            if not file_path_abs.exists():
                 raise ValueError('file not found', filename)
 
-            with io.open(file_path_abs, encoding='utf8') as f:
-                text_to_include = f.read()
+            text_to_include = file_path_abs.read_text(encoding='utf8')
 
             # Allow good practice of having a final newline in the file
             if text_to_include.endswith('\n'):
@@ -60,13 +58,12 @@ class ImportMarkdownPlugin(mkdocs.plugins.BasePlugin):
             start = match.group('start')
             end = match.group('end')
 
-            file_path_abs = os.path.join(os.path.dirname(page_src_path), filename)
+            file_path_abs = Path(page_src_path).parent / filename
 
-            if not os.path.exists(file_path_abs):
+            if not file_path_abs.exists():
                 raise ValueError('file not found', filename)
 
-            with io.open(file_path_abs, encoding='utf8') as f:
-                text_to_include = f.read()
+            text_to_include = file_path_abs.read_text(encoding='utf8')
 
             if start:
                 _, _, text_to_include = text_to_include.partition(start)

docs/options.md

@@ -52,7 +52,6 @@ env:
 
 ## Build selection
 
-
 ### `CIBW_PLATFORM` {: #platform}
 
 > Override the auto-detected target platform
@@ -67,6 +66,7 @@ For `linux` you need Docker running, on macOS or Linux. For `macos`, you need a
 
 This option can also be set using the command-line option `--platform`.
 
+
 ### `CIBW_BUILD`, `CIBW_SKIP` {: #build-skip}
 
 > Choose the Python versions to build
@@ -155,7 +155,6 @@ CIBW_SKIP: pp*
 
 ## Build customization
 
-
 ### `CIBW_ENVIRONMENT` {: #environment}
 > Set environment variables needed during the build
 
@@ -191,6 +190,28 @@ CIBW_ENVIRONMENT: "BUILD_TIME=$(date) SAMPLE_TEXT=\"sample text\""
 !!! note
     `cibuildwheel` always defines the environment variable `CIBUILDWHEEL=1`. This can be useful for [building wheels with optional extensions](faq.md#building-packages-with-optional-c-extensions).
 
+### `CIBW_BEFORE_ALL` {: #before-all}
+> Execute a shell command on the build system before any wheels are built.
+
+Shell command to prepare a common part of the project (e.g. build or install libraries which does not depend on the specific version of Python).
+
+This option is very useful for the Linux build, where builds take place in isolated Docker containers managed by cibuildwheel. This command will run inside the container before the wheel builds start. Note, if you're building both x86_64 and i686 wheels (the default), your build uses two different Docker images. In that case, this command will execute twice - once per build container.
+
+The placeholder `{package}` can be used here; it will be replaced by the path to the package being built by `cibuildwheel`.
+
+On Windows and macOS, the version of Python available inside `CIBW_BEFORE_ALL` is whatever is available on the host machine. On Linux, a modern Python version is available on PATH.
+
+Platform-specific variants also available:<br/>
+ `CIBW_BEFORE_ALL_MACOS` | `CIBW_BEFORE_ALL_WINDOWS` | `CIBW_BEFORE_ALL_LINUX`
+
+#### Examples
+```yaml
+# build third party library
+CIBW_BEFORE_ALL: make -C third_party_lib
+
+# install system library
+CIBW_BEFORE_ALL_LINUX: yum install -y libffi-dev
+```
 
 ### `CIBW_BEFORE_BUILD` {: #before-build}
 > Execute a shell command preparing each wheel's build
@@ -296,6 +317,7 @@ CIBW_MANYLINUX_X86_64_IMAGE: dockcross/manylinux-x64
 CIBW_MANYLINUX_I686_IMAGE: dockcross/manylinux-x86
 ```
 
+
 ### `CIBW_DEPENDENCY_VERSIONS` {: #dependency-versions}
 > Specify how cibuildwheel controls the versions of the tools it uses
 
@@ -372,6 +394,35 @@ CIBW_TEST_COMMAND: pytest {package}/tests
 ```
 
 
+### `CIBW_BEFORE_TEST` {: #before-test}
+> Execute a shell command before testing each wheel
+
+A shell command to run in **each** test virtual environment, before your wheel is installed and tested. This is useful if you need to install a non pip package, change values of environment variables
+or perform multi step pip installation (e.g. installing `scikit-build` or `cython` before install test package)
+
+The active Python binary can be accessed using `python`, and pip with `pip`; `cibuildwheel` makes sure the right version of Python and pip will be executed. The placeholder `{package}` can be used here; it will be replaced by the path to the package being built by `cibuildwheel`.
+
+The command is run in a shell, so you can write things like `cmd1 && cmd2`.
+
+Platform-specific variants also available:<br/>
+ `CIBW_BEFORE_TEST_MACOS` | `CIBW_BEFORE_TEST_WINDOWS` | `CIBW_BEFORE_TEST_LINUX`
+
+#### Examples
+```yaml
+# install test dependencies with overwritten environment variables.
+CIBW_BEFORE_TEST: CC=gcc CXX=g++ pip install -r requirements.txt
+
+# chain commands using &&
+CIBW_BEFORE_TEST: rm -rf ./data/cache && mkdir -p ./data/cache
+
+# install non pip python package
+CIBW_BEFORE_TEST: cd some_dir; ./configure; make; make install
+
+# install python packages that are required to install test dependencies
+CIBW_BEFORE_TEST: pip install cmake scikit-build
+```
+
+
 ### `CIBW_TEST_REQUIRES` {: #test-requires}
 > Install Python dependencies before running the tests
 
@@ -411,33 +462,6 @@ Platform-specific variants also available:<br/>
 CIBW_TEST_EXTRAS: test,qt
 ```
 
-### `CIBW_BEFORE_TEST` {: #before-test}
-> Execute a shell command before testing each wheel
-
-A shell command to run in **each** test virtual environment, before your wheel is installed and tested. This is useful if you need to install a non pip package, change values of environment variables
-or perform multi step pip installation (e.g. installing `scikit-build` or `cython` before install test package)
-
-The active Python binary can be accessed using `python`, and pip with `pip`; `cibuildwheel` makes sure the right version of Python and pip will be executed. The placeholder `{package}` can be used here; it will be replaced by the path to the package being built by `cibuildwheel`.
-
-The command is run in a shell, so you can write things like `cmd1 && cmd2`.
-
-Platform-specific variants also available:<br/>
- `CIBW_BEFORE_TEST_MACOS` | `CIBW_BEFORE_TEST_WINDOWS` | `CIBW_BEFORE_TEST_LINUX`
-
-#### Examples
-```yaml
-# install test dependencies with overwritten environment variables.
-CIBW_BEFORE_TEST: CC=gcc CXX=g++ pip install -r requirements.txt
-
-# chain commands using &&
-CIBW_BEFORE_TEST: rm -rf ./data/cache && mkdir -p ./data/cache
-
-# install non pip python package
-CIBW_BEFORE_TEST: cd some_dir; ./configure; make; make install
-
-# install python packages that are required to install test dependencies
-CIBW_BEFORE_TEST: pip install cmake scikit-build
-```
 
 ## Other
 
@@ -601,7 +625,7 @@ optional arguments:
         var url = 'https://cibuildwheel.readthedocs.io/en/stable/options/#'+option.id;
         var namesMarkdown = $.map(optionNames, function(n) {
           return '[`'+n+'`]('+url+') '
-        }).join(' ')
+        }).join(' <br> ')
 
         markdown += '| '+namesMarkdown+' '
         markdown += '| '+option.description.trim()+' '

docs/setup.md

@@ -15,6 +15,8 @@ Commit this file, and push to Github - either to your default branch, or to a PR
 
 For more info on this file, check out the [docs](https://help.github.com/en/actions/reference/workflow-syntax-for-github-actions).
 
+[`examples/github-deploy.yml`](https://github.com/joerick/cibuildwheel/blob/master/examples/github-deploy.yml) extends this minimal example with a demonstration of how to automatically upload the built wheels to PyPI.
+
 # Azure Pipelines [linux/mac/windows] {: #azure-pipelines}
 
 To build Linux, Mac, and Windows wheels on Azure Pipelines, create a `azure-pipelines.yml` file in your repo.
@@ -46,6 +48,8 @@ Commit this file, enable building of your repo on Travis CI, and push.
 
 Then setup a deployment method by following the [Travis CI deployment docs](https://docs.travis-ci.com/user/deployment/), or see [Delivering to PyPI](deliver-to-pypi.md). For more info on `.travis.yml`, check out the [docs](https://docs.travis-ci.com/).
 
+[`examples/travis-deploy.yml`](https://github.com/joerick/cibuildwheel/blob/master/examples/travis-deploy.yml) extends this minimal example with a demonstration of how to automatically upload the built wheels to PyPI.
+
 # CircleCI [linux/mac] {: #circleci}
 
 To build Linux and Mac wheels on CircleCI, create a `.circleci/config.yml` file in your repo,

examples/appveyor-minimal.yml

@@ -12,7 +12,7 @@ stack: python 3.7
 init:
 - cmd: set PATH=C:\Python37;C:\Python37\Scripts;%PATH%
 
-install: python -m pip install cibuildwheel==1.4.2
+install: python -m pip install cibuildwheel==1.5.3
 
 build_script: python -m cibuildwheel --output-dir wheelhouse
 

examples/azure-pipelines-minimal.yml

@@ -5,7 +5,7 @@ jobs:
     - task: UsePythonVersion@0
     - bash: |
         python3 -m pip install --upgrade pip
-        pip3 install cibuildwheel==1.4.2
+        pip3 install cibuildwheel==1.5.3
         cibuildwheel --output-dir wheelhouse .
     - task: PublishBuildArtifacts@1
       inputs: {pathtoPublish: 'wheelhouse'}
@@ -16,7 +16,7 @@ jobs:
     - task: UsePythonVersion@0
     - bash: |
         python3 -m pip install --upgrade pip
-        pip3 install cibuildwheel==1.4.2
+        pip3 install cibuildwheel==1.5.3
         cibuildwheel --output-dir wheelhouse .
     - task: PublishBuildArtifacts@1
       inputs: {pathtoPublish: 'wheelhouse'}
@@ -29,7 +29,7 @@ jobs:
       displayName: Install Visual C++ for Python 2.7
     - bash: |
         python -m pip install --upgrade pip
-        pip install cibuildwheel==1.4.2
+        pip install cibuildwheel==1.5.3
         cibuildwheel --output-dir wheelhouse .
     - task: PublishBuildArtifacts@1
       inputs: {pathtoPublish: 'wheelhouse'}

examples/circleci-minimal.yml

@@ -11,7 +11,7 @@ jobs:
       - run:
           name: Build the Linux wheels.
           command: |
-            pip3 install --user cibuildwheel==1.4.2
+            pip3 install --user cibuildwheel==1.5.3
             cibuildwheel --output-dir wheelhouse
       - store_artifacts:
           path: wheelhouse/
@@ -25,7 +25,7 @@ jobs:
       - run:
           name: Build the OS X wheels.
           command: |
-            pip3 install --user cibuildwheel==1.4.2
+            pip3 install --user cibuildwheel==1.5.3
             cibuildwheel --output-dir wheelhouse
       - store_artifacts:
           path: wheelhouse/

examples/github-deploy.yml

@@ -0,0 +1,81 @@
+name: Build and upload to PyPI
+
+# Build on every branch push, tag push, and pull request change:
+on: [push, pull_request]
+# Alternatively, to publish when a (published) GitHub Release is created, use the following:
+# on:
+#   push:
+#   pull_request:
+#   release:
+#     types:
+#       - published
+
+jobs:
+  build_wheels:
+    name: Build wheels on ${{ matrix.os }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-18.04, windows-latest, macos-latest]
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - uses: actions/setup-python@v2
+        name: Install Python
+        with:
+          python-version: '3.7'
+
+      - name: Install cibuildwheel
+        run: |
+          python -m pip install cibuildwheel==1.5.3
+
+      - name: Install Visual C++ for Python 2.7
+        if: runner.os == 'Windows'
+        run: |
+          choco install vcpython27 -f -y
+
+      - name: Build wheels
+        run: |
+          python -m cibuildwheel --output-dir wheelhouse
+
+      - uses: actions/upload-artifact@v2
+        with:
+          path: ./wheelhouse/*.whl
+
+  build_sdist:
+    name: Build source distribution
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+
+      - uses: actions/setup-python@v2
+        name: Install Python
+        with:
+          python-version: '3.7'
+
+      - name: Build sdist
+        run: python setup.py sdist
+
+      - uses: actions/upload-artifact@v2
+        with:
+          path: dist/*.tar.gz
+
+  upload_pypi:
+    needs: [build_wheels, build_sdist]
+    runs-on: ubuntu-latest
+    # upload to PyPI on every tag starting with 'v'
+    if: github.event_name == 'push' && startsWith(github.event.ref, 'refs/tags/v')
+    # alternatively, to publish when a GitHub Release is created, use the following rule:
+    # if: github.event_name == 'release' && github.event.action == 'published'
+    steps:
+      - uses: actions/download-artifact@v2
+        with:
+          name: artifact
+          path: dist
+
+      - uses: pypa/gh-action-pypi-publish@master
+        with:
+          user: __token__
+          password: ${{ secrets.pypi_password }}
+          # To test: repository_url: https://test.pypi.org/legacy/

examples/github-minimal.yml

@@ -4,34 +4,33 @@ on: [push, pull_request]
 
 jobs:
   build_wheels:
-    name: Build wheel on ${{ matrix.os }}
+    name: Build wheels on ${{ matrix.os }}
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
         os: [ubuntu-18.04, windows-latest, macos-latest]
 
     steps:
-    - uses: actions/checkout@v1
+      - uses: actions/checkout@v2
 
-    - uses: actions/setup-python@v1
-      name: Install Python
-      with:
-        python-version: '3.7'
+      - uses: actions/setup-python@v2
+        name: Install Python
+        with:
+          python-version: '3.7'
 
-    - name: Install cibuildwheel
-      run: |
-        python -m pip install cibuildwheel==1.4.2
+      - name: Install cibuildwheel
+        run: |
+          python -m pip install cibuildwheel==1.5.3
 
-    - name: Install Visual C++ for Python 2.7
-      if: startsWith(matrix.os, 'windows')
-      run: |
-        choco install vcpython27 -f -y
+      - name: Install Visual C++ for Python 2.7
+        if: runner.os == 'Windows'
+        run: |
+          choco install vcpython27 -f -y
 
-    - name: Build wheel
-      run: |
-        python -m cibuildwheel --output-dir wheelhouse
+      - name: Build wheels
+        run: |
+          python -m cibuildwheel --output-dir wheelhouse
 
-    - uses: actions/upload-artifact@v1
-      with:
-        name: wheels
-        path: ./wheelhouse
+      - uses: actions/upload-artifact@v2
+        with:
+          path: ./wheelhouse/*.whl

examples/travis-ci-deploy.yml

@@ -25,7 +25,7 @@ env:
     # Note: TWINE_PASSWORD is set to a PyPI API token in Travis settings
 
 install:
-  - python3 -m pip install cibuildwheel==1.4.2
+  - python3 -m pip install cibuildwheel==1.5.3
 
 script:
   # build the wheels, put them into './wheelhouse'

examples/travis-ci-minimal.yml

@@ -26,7 +26,7 @@ jobs:
         - ln -s /c/Python38/python.exe /c/Python38/python3.exe
 
 install:
-  - python3 -m pip install cibuildwheel==1.4.2
+  - python3 -m pip install cibuildwheel==1.5.3
 
 script:
   # build the wheels, put them into './wheelhouse'

examples/travis-ci-test-and-deploy.yml

@@ -55,7 +55,7 @@ jobs:
     - stage: deploy
       name: Build and deploy Linux wheels
       services: docker
-      install: python3 -m pip install cibuildwheel==1.4.2
+      install: python3 -m pip install cibuildwheel==1.5.3
       script: python3 -m cibuildwheel --output-dir wheelhouse
       after_success: |
         python3 -m pip install twine
@@ -65,7 +65,7 @@ jobs:
       name: Build and deploy macOS wheels
       os: osx
       language: shell
-      install: python3 -m pip install cibuildwheel==1.4.2
+      install: python3 -m pip install cibuildwheel==1.5.3
       script: python3 -m cibuildwheel --output-dir wheelhouse
       after_success: |
         python3 -m pip install twine
@@ -75,7 +75,7 @@ jobs:
       name: Build and deploy Windows wheels
       os: windows
       language: shell
-      install: python3 -m pip install cibuildwheel==1.4.2
+      install: python3 -m pip install cibuildwheel==1.5.3
       script: python3 -m cibuildwheel --output-dir wheelhouse
       after_success: |
         python3 -m pip install twine

requirements-dev.txt

@@ -6,3 +6,5 @@ pymdown-extensions
 pip-tools
 requests
 click
+mypy
+typing-extensions

setup.cfg

@@ -1,5 +1,5 @@
 [flake8]
-ignore = E501,W503,E741
+ignore = E501,W503,E741,E226
 application-import-names = cibuildwheel
 exclude =
   cibuildwheel/resources/,

setup.py

@@ -1,20 +1,18 @@
 # -*- coding: utf-8 -*-
-import io
-import os
+from pathlib import Path
 
 try:
     from setuptools import setup
 except ImportError:
     from distutils.core import setup
 
-this_directory = os.path.dirname(__file__)
-with io.open(os.path.join(this_directory, 'README.md'), encoding='utf-8') as f:
-    long_description = f.read()
+this_directory = Path(__file__).parent
+long_description = (this_directory / 'README.md').read_text(encoding='utf-8')
 
 setup(
     name='cibuildwheel',
-    version='1.4.2',
-    install_requires=['bashlex!=0.13'],
+    version='1.5.3',
+    install_requires=['bashlex!=0.13', 'toml'],
     description="Build Python wheels on CI with minimal configuration.",
     long_description=long_description,
     long_description_content_type='text/markdown',

test/test_before_all.py

@@ -0,0 +1,38 @@
+import os
+import textwrap
+
+from . import utils
+from . import test_projects
+
+project_with_before_build_asserts = test_projects.new_c_project(
+    setup_py_add=textwrap.dedent(r'''
+        # assert that the Python version as written to text_info.txt in the CIBW_BEFORE_ALL step
+        # is the same one as is currently running.
+        with open("text_info.txt") as f:
+            stored_text = f.read()
+
+        print("## stored text: " + stored_text)
+        assert stored_text == "sample text 123"
+    ''')
+)
+
+
+def test(tmp_path):
+    project_dir = tmp_path / 'project'
+    project_with_before_build_asserts.generate(project_dir)
+
+    with open(os.path.join(project_dir, "text_info.txt"), mode='w') as ff:
+        print("dummy text", file=ff)
+
+    # build the wheels
+    actual_wheels = utils.cibuildwheel_run(project_dir, add_env={
+        # write python version information to a temporary file, this is
+        # checked in setup.py
+        'CIBW_BEFORE_ALL': '''python -c "import os;open('{project}/text_info.txt', 'w').write('sample text '+os.environ.get('TEST_VAL', ''))"''',
+        'CIBW_ENVIRONMENT': "TEST_VAL='123'"
+    })
+
+    # also check that we got the right wheels
+    os.remove(os.path.join(project_dir, "text_info.txt"))
+    expected_wheels = utils.expected_wheels('spam', '0.1.0')
+    assert set(actual_wheels) == set(expected_wheels)

test/test_dependency_versions.py

@@ -1,4 +1,3 @@
-import os
 import re
 import pytest
 import textwrap
@@ -39,11 +38,9 @@ VERSION_REGEX = r'([\w-]+)==([^\s]+)'
 
 
 def get_versions_from_constraint_file(constraint_file):
-    with open(constraint_file, encoding='utf8') as f:
-        constraint_file_text = f.read()
+    constraint_file_text = constraint_file.read_text(encoding='utf8')
 
     versions = {}
-
     for package, version in re.findall(VERSION_REGEX, constraint_file_text):
         versions[package] = version
 
@@ -73,7 +70,7 @@ def test_pinned_versions(tmp_path, python_version):
         constraint_filename = 'constraints.txt'
         build_pattern = '[cp]p38-*'
 
-    constraint_file = os.path.join(cibuildwheel.util.resources_dir, constraint_filename)
+    constraint_file = cibuildwheel.util.resources_dir / constraint_filename
     constraint_versions = get_versions_from_constraint_file(constraint_file)
 
     for package in ['pip', 'setuptools', 'wheel', 'virtualenv']:

test/test_environment.py

@@ -44,7 +44,7 @@ def test(tmp_path):
     assert set(actual_wheels) == set(expected_wheels)
 
 
-def test_overridden_path(tmp_path):
+def test_overridden_path(tmp_path, capfd):
     project_dir = tmp_path / 'project'
     output_dir = tmp_path / 'output'
 
@@ -54,8 +54,21 @@ def test_overridden_path(tmp_path):
 
     # mess up PATH, somehow
     with pytest.raises(subprocess.CalledProcessError):
-        utils.cibuildwheel_run(project_dir, output_dir=output_dir, add_env={
-            'CIBW_ENVIRONMENT': '''SOMETHING="$(mkdir new_path && touch new_path/python)" PATH="$(realpath new_path):$PATH"''',
-            'CIBW_ENVIRONMENT_WINDOWS': '''SOMETHING="$(mkdir new_path && type nul > new_path/python.exe)" PATH="$CD\\new_path;$PATH"''',
-        })
+        if utils.platform == 'linux':
+            utils.cibuildwheel_run(project_dir, output_dir=output_dir, add_env={
+                'CIBW_BEFORE_ALL': 'mkdir new_path && touch new_path/python && chmod +x new_path/python',
+                'CIBW_ENVIRONMENT': '''PATH="$(pwd)/new_path:$PATH"''',
+            })
+        else:
+            new_path = tmp_path / 'another_bin'
+            new_path.mkdir()
+            (new_path / 'python').touch(mode=0o777)
+
+            utils.cibuildwheel_run(project_dir, output_dir=output_dir, add_env={
+                'NEW_PATH': str(new_path),
+                'CIBW_ENVIRONMENT': f'''PATH="$NEW_PATH{os.pathsep}$PATH"''',
+            })
+
     assert len(os.listdir(output_dir)) == 0
+    captured = capfd.readouterr()
+    assert "python available on PATH doesn't match our installed instance" in captured.err

test/test_pep518.py

@@ -0,0 +1,49 @@
+import textwrap
+from . import test_projects
+from . import utils
+
+basic_project = test_projects.new_c_project(
+    setup_py_add=textwrap.dedent(
+        """
+        # Will fail if PEP 518 does work
+        import sys
+        import requests
+        if sys.version_info < (3, 6, 0):
+            assert requests.__version__ == "2.22.0", "Requests found but wrong version ({0})".format(requests.__version__)
+        else:
+            assert requests.__version__ == "2.23.0", "Requests found but wrong version ({0})".format(requests.__version__)
+
+        # Just making sure environment is still set
+        import os
+        if os.environ.get("CIBUILDWHEEL", "0") != "1":
+            raise Exception("CIBUILDWHEEL environment variable is not set to 1")
+        """
+    )
+)
+
+basic_project.files[
+    "pyproject.toml"
+] = """
+[build-system]
+requires = [
+    "setuptools >= 42",
+    "wheel",
+    "requests==2.22.0; python_version<'3.6'",
+    "requests==2.23.0; python_version>='3.6'"
+]
+
+build-backend = "setuptools.build_meta"
+"""
+
+
+def test_pep518(tmp_path):
+
+    project_dir = tmp_path / "project"
+    basic_project.generate(project_dir)
+
+    # build the wheels
+    actual_wheels = utils.cibuildwheel_run(project_dir)
+
+    # check that the expected wheels are produced
+    expected_wheels = utils.expected_wheels("spam", "0.1.0")
+    assert set(actual_wheels) == set(expected_wheels)

test/test_projects/__main__.py

@@ -1,8 +1,9 @@
-from argparse import ArgumentParser
 import importlib
-import tempfile
-import sys
 import subprocess
+import sys
+import tempfile
+from argparse import ArgumentParser
+from pathlib import Path
 
 
 def main():
@@ -19,7 +20,7 @@ def main():
 
     project = getattr(importlib.import_module(module), name)
 
-    project_dir = tempfile.mkdtemp()
+    project_dir = Path(tempfile.mkdtemp())
     project.generate(project_dir)
 
     print('Project generated at', project_dir)

test/test_projects/base.py

@@ -1,5 +1,7 @@
-import os
+from pathlib import Path
+
 import jinja2
+
 from typing import Union, Dict, Any
 
 
@@ -14,6 +16,8 @@ class TestProject:
 
     Write out to the filesystem using `generate`.
     '''
+    __test__ = False  # Have pytest ignore this class on `from .test_projects import TestProject`
+
     files: FilesDict
     template_context: TemplateContext
 
@@ -21,12 +25,12 @@ class TestProject:
         self.files = {}
         self.template_context = {}
 
-    def generate(self, path: str):
+    def generate(self, path: Path):
         for filename, content in self.files.items():
-            file_path = os.path.join(path, filename)
-            os.makedirs(os.path.dirname(file_path), exist_ok=True)
+            file_path = path / filename
+            file_path.parent.mkdir(parents=True, exist_ok=True)
 
-            with open(file_path, 'w', encoding='utf8') as f:
+            with file_path.open('w', encoding='utf8') as f:
                 if isinstance(content, jinja2.Template):
                     content = content.render(self.template_context)
 

test/test_subdir_package.py

@@ -1,4 +1,4 @@
-import os
+from pathlib import Path
 
 import jinja2
 
@@ -35,7 +35,7 @@ def test(capfd, tmp_path):
     project_dir = tmp_path / 'project'
     subdir_package_project.generate(project_dir)
 
-    package_dir = os.path.join(project_dir, 'src', 'spam')
+    package_dir = Path('src', 'spam')
     # build the wheels
     actual_wheels = utils.cibuildwheel_run(project_dir, package_dir=package_dir, add_env={
         'CIBW_BEFORE_BUILD': 'python {project}/bin/before_build.py',

test/test_testing.py

@@ -46,12 +46,15 @@ class TestSpam(TestCase):
         self.assertNotEqual(0, spam.system('python -c "exit(1)"'))
 
     def test_virtualenv(self):
-        virtualenv_path = os.environ.get("__CIBW_VIRTUALENV_PATH__")
-        if not virtualenv_path:
-            self.fail("No virtualenv path defined in environment variable __CIBW_VIRTUALENV_PATH__")
+        # sys.prefix is different from sys.base_prefix when running a virtualenv
+        # See https://docs.python.org/3/library/venv.html, which virtualenv seems
+        # to honor in recent releases
+        # Python 2 doesn't have sys.base_prefix by default
+        if not hasattr(sys, 'base_prefix') or sys.prefix == sys.base_prefix:
+            self.fail("Not running in a virtualenv")
 
-        self.assertTrue(path_contains(virtualenv_path, sys.executable))
-        self.assertTrue(path_contains(virtualenv_path, spam.__file__))
+        self.assertTrue(path_contains(sys.prefix, sys.executable))
+        self.assertTrue(path_contains(sys.prefix, spam.__file__))
 
     def test_uname(self):
         if platform.system() == "Windows":

test/utils.py

@@ -10,9 +10,10 @@ import shutil
 import subprocess
 import sys
 from contextlib import contextmanager
+from pathlib import Path
 from tempfile import mkdtemp
 
-IS_WINDOWS_RUNNING_ON_AZURE = os.path.exists('C:\\hostedtoolcache')
+IS_WINDOWS_RUNNING_ON_AZURE = Path('C:\\hostedtoolcache').exists()
 IS_WINDOWS_RUNNING_ON_TRAVIS = os.environ.get('TRAVIS_OS_NAME') == 'windows'
 
 
@@ -66,7 +67,7 @@ def cibuildwheel_run(project_path, package_dir='.', env=None, add_env=None, outp
 
     with TemporaryDirectoryIfNone(output_dir) as _output_dir:
         subprocess.check_call(
-            [sys.executable, '-m', 'cibuildwheel', '--output-dir', str(_output_dir), package_dir],
+            [sys.executable, '-m', 'cibuildwheel', '--output-dir', str(_output_dir), str(package_dir)],
             env=env,
             cwd=project_path,
         )

unit_test/conftest.py

@@ -0,0 +1,21 @@
+import pytest
+
+
+def pytest_addoption(parser):
+    parser.addoption(
+        "--run-docker", action="store_true", default=False, help="run docker tests"
+    )
+
+
+def pytest_configure(config):
+    config.addinivalue_line("markers", "docker: mark test requiring docker to run")
+
+
+def pytest_collection_modifyitems(config, items):
+    if config.getoption("--run-docker"):
+        # --run-docker given in cli: do not skip docker tests
+        return
+    skip_docker = pytest.mark.skip(reason="need --run-docker option to run")
+    for item in items:
+        if "docker" in item.keywords:
+            item.add_marker(skip_docker)

unit_test/dependency_constraints_test.py

@@ -1,30 +1,16 @@
 from cibuildwheel.util import DependencyConstraints
-import os
+
+from pathlib import Path
 
 
 def test_defaults():
     dependency_constraints = DependencyConstraints.with_defaults()
 
-    project_root = os.path.dirname(os.path.dirname(__file__))
-    resources_dir = os.path.join(project_root, 'cibuildwheel', 'resources')
+    project_root = Path(__file__).parents[1]
+    resources_dir = project_root / 'cibuildwheel' / 'resources'
 
-    assert os.path.samefile(
-        dependency_constraints.base_file_path,
-        os.path.join(resources_dir, 'constraints.txt')
-    )
-    assert os.path.samefile(
-        dependency_constraints.get_for_python_version('3.8'),
-        os.path.join(resources_dir, 'constraints.txt')
-    )
-    assert os.path.samefile(
-        dependency_constraints.get_for_python_version('3.6'),
-        os.path.join(resources_dir, 'constraints-python36.txt')
-    )
-    assert os.path.samefile(
-        dependency_constraints.get_for_python_version('3.5'),
-        os.path.join(resources_dir, 'constraints-python35.txt')
-    )
-    assert os.path.samefile(
-        dependency_constraints.get_for_python_version('2.7'),
-        os.path.join(resources_dir, 'constraints-python27.txt')
-    )
+    assert dependency_constraints.base_file_path.samefile(resources_dir / 'constraints.txt')
+    assert dependency_constraints.get_for_python_version('3.8').samefile(resources_dir / 'constraints.txt')
+    assert dependency_constraints.get_for_python_version('3.6').samefile(resources_dir / 'constraints-python36.txt')
+    assert dependency_constraints.get_for_python_version('3.5').samefile(resources_dir / 'constraints-python35.txt')
+    assert dependency_constraints.get_for_python_version('2.7').samefile(resources_dir / 'constraints-python27.txt')

unit_test/docker_container_test.py

@@ -0,0 +1,147 @@
+import platform
+import random
+import shutil
+import subprocess
+import textwrap
+from pathlib import Path, PurePath
+
+import pytest
+
+from cibuildwheel.docker_container import DockerContainer
+
+# for these tests we use manylinux2014 images, because they're available on
+# multi architectures and include python3.8
+pm = platform.machine()
+if pm == "x86_64":
+    DEFAULT_IMAGE = 'quay.io/pypa/manylinux2014_x86_64:2020-05-17-2f8ac3b'
+elif pm == "aarch64":
+    DEFAULT_IMAGE = 'quay.io/pypa/manylinux2014_aarch64:2020-05-17-2f8ac3b'
+elif pm == "ppc64le":
+    DEFAULT_IMAGE = 'quay.io/pypa/manylinux2014_ppc64le:2020-05-17-2f8ac3b'
+elif pm == "s390x":
+    DEFAULT_IMAGE = 'quay.io/pypa/manylinux2014_s390x:2020-05-17-2f8ac3b'
+
+
+@pytest.mark.docker
+def test_simple():
+    with DockerContainer(DEFAULT_IMAGE) as container:
+        assert container.call(['echo', 'hello'], capture_output=True) == 'hello\n'
+
+
+@pytest.mark.docker
+def test_no_lf():
+    with DockerContainer(DEFAULT_IMAGE) as container:
+        assert container.call(['printf', 'hello'], capture_output=True) == 'hello'
+
+
+@pytest.mark.docker
+def test_environment():
+    with DockerContainer(DEFAULT_IMAGE) as container:
+        assert container.call(['sh', '-c', 'echo $TEST_VAR'], env={'TEST_VAR': '1'}, capture_output=True) == '1\n'
+
+
+@pytest.mark.docker
+def test_container_removed():
+    with DockerContainer(DEFAULT_IMAGE) as container:
+        docker_containers_listing = subprocess.run('docker container ls', shell=True, check=True, stdout=subprocess.PIPE, universal_newlines=True).stdout
+        assert container.name in docker_containers_listing
+        old_container_name = container.name
+
+    docker_containers_listing = subprocess.run('docker container ls', shell=True, check=True, stdout=subprocess.PIPE, universal_newlines=True).stdout
+    assert old_container_name not in docker_containers_listing
+
+
+@pytest.mark.docker
+def test_large_environment():
+    # max environment variable size is 128kB
+    long_env_var_length = 127*1024
+    large_environment = {
+        'a': '0'*long_env_var_length,
+        'b': '0'*long_env_var_length,
+        'c': '0'*long_env_var_length,
+        'd': '0'*long_env_var_length,
+    }
+
+    with DockerContainer(DEFAULT_IMAGE) as container:
+        # check the length of d
+        assert container.call(['sh', '-c', 'echo ${#d}'], env=large_environment, capture_output=True) == f'{long_env_var_length}\n'
+
+
+@pytest.mark.docker
+def test_binary_output():
+    with DockerContainer(DEFAULT_IMAGE) as container:
+        # note: the below embedded snippets are in python2
+
+        # check that we can pass though arbitrary binary data without erroring
+        container.call(['/usr/bin/python2', '-c', textwrap.dedent('''
+            import sys
+            sys.stdout.write(''.join(chr(n) for n in range(0, 256)))
+        ''')])
+
+        # check that we can capture arbitrary binary data
+        output = container.call(['/usr/bin/python2', '-c', textwrap.dedent('''
+            import sys
+            sys.stdout.write(''.join(chr(n % 256) for n in range(0, 512)))
+        ''')], capture_output=True)
+
+        data = bytes(output, encoding='utf8', errors='surrogateescape')
+
+        for i in range(0, 512):
+            assert data[i] == i % 256
+
+        # check that environment variables can carry binary data, except null characters
+        # (https://www.gnu.org/software/libc/manual/html_node/Environment-Variables.html)
+        binary_data = bytes(n for n in range(1, 256))
+        binary_data_string = str(binary_data, encoding='utf8', errors='surrogateescape')
+        output = container.call(
+            ['python2', '-c', 'import os, sys; sys.stdout.write(os.environ["TEST_VAR"])'],
+            env={'TEST_VAR': binary_data_string},
+            capture_output=True,
+        )
+        assert output == binary_data_string
+
+
+@pytest.mark.docker
+def test_file_operations(tmp_path: Path):
+    with DockerContainer(DEFAULT_IMAGE) as container:
+        # test copying a file in
+        test_binary_data = bytes(random.randrange(256) for _ in range(1000))
+        original_test_file = tmp_path / 'test.dat'
+        original_test_file.write_bytes(test_binary_data)
+
+        dst_file = PurePath('/tmp/test.dat')
+
+        container.copy_into(original_test_file, dst_file)
+
+        output = container.call(['cat', dst_file], capture_output=True)
+        assert test_binary_data == bytes(output, encoding='utf8', errors='surrogateescape')
+
+
+@pytest.mark.docker
+def test_dir_operations(tmp_path: Path):
+    with DockerContainer(DEFAULT_IMAGE) as container:
+        test_binary_data = bytes(random.randrange(256) for _ in range(1000))
+        original_test_file = tmp_path / 'test.dat'
+        original_test_file.write_bytes(test_binary_data)
+
+        # test copying a dir in
+        test_dir = tmp_path / 'test_dir'
+        test_dir.mkdir()
+        test_file = test_dir / 'test.dat'
+        shutil.copyfile(original_test_file, test_file)
+
+        dst_dir = PurePath('/tmp/test_dir')
+        dst_file = dst_dir / 'test.dat'
+        container.copy_into(test_dir, dst_dir)
+
+        output = container.call(['cat', dst_file], capture_output=True)
+        assert test_binary_data == bytes(output, encoding='utf8', errors='surrogateescape')
+
+        # test glob
+        assert container.glob(dst_dir, '*.dat') == [dst_file]
+
+        # test copy dir out
+        new_test_dir = tmp_path / 'test_dir_new'
+        container.copy_out(dst_dir, new_test_dir)
+
+        assert test_binary_data == (new_test_dir / 'test.dat').read_bytes()

unit_test/environment_test.py

@@ -94,3 +94,32 @@ def test_no_vars_pass_through():
     environment_dict = environment_recipe.as_dictionary(prev_environment={'CIBUILDWHEEL': 'awesome'})
 
     assert environment_dict == {'CIBUILDWHEEL': 'awesome'}
+
+
+def test_operators_inside_eval():
+    environment_recipe = parse_environment('SOMETHING="$(echo a; echo b; echo c)"')
+
+    # pass the existing process env so PATH is available
+    environment_dict = environment_recipe.as_dictionary(os.environ.copy())
+
+    assert environment_dict.get('SOMETHING') == 'a\nb\nc'
+
+
+def test_substitution_with_backslash():
+    environment_recipe = parse_environment('PATH2="somewhere_else;$PATH1"')
+
+    # pass the existing process env so PATH is available
+    environment_dict = environment_recipe.as_dictionary(prev_environment={
+        'PATH1': 'c:\\folder\\'
+    })
+
+    assert environment_dict.get('PATH2') == 'somewhere_else;c:\\folder\\'
+
+
+def test_awkwardly_quoted_variable():
+    environment_recipe = parse_environment('VAR2=something"like this""$VAR1"$VAR1$(echo "theres more")"$(echo "and more!")"')
+
+    # pass the existing process env so PATH is available
+    environment_dict = environment_recipe.as_dictionary({'VAR1': 'but wait'})
+
+    assert environment_dict.get('VAR2') == 'somethinglike thisbut waitbut waittheres moreand more!'

unit_test/main_tests/conftest.py

@@ -1,6 +1,6 @@
-import os
 import subprocess
 import sys
+from pathlib import Path
 
 import pytest
 
@@ -18,7 +18,7 @@ class ArgsInterceptor:
         self.kwargs = kwargs
 
 
-MOCK_PACKAGE_DIR = 'some_package_dir'
+MOCK_PACKAGE_DIR = Path('some_package_dir')
 
 
 @pytest.fixture(autouse=True)
@@ -31,28 +31,33 @@ def mock_protection(monkeypatch):
     def fail_on_call(*args, **kwargs):
         raise RuntimeError("This should never be called")
 
+    def ignore_call(*args, **kwargs):
+        pass
+
     monkeypatch.setattr(subprocess, 'Popen', fail_on_call)
     monkeypatch.setattr(util, 'download', fail_on_call)
     monkeypatch.setattr(windows, 'build', fail_on_call)
     monkeypatch.setattr(linux, 'build', fail_on_call)
     monkeypatch.setattr(macos, 'build', fail_on_call)
 
+    monkeypatch.setattr(Path, 'mkdir', ignore_call)
+
 
 @pytest.fixture(autouse=True)
 def fake_package_dir(monkeypatch):
     '''
     Monkey-patch enough for the main() function to run
     '''
-    real_os_path_exists = os.path.exists
+    real_path_exists = Path.exists
 
-    def mock_os_path_exists(path):
-        if path == os.path.join(MOCK_PACKAGE_DIR, 'setup.py'):
+    def mock_path_exists(path):
+        if path == MOCK_PACKAGE_DIR / 'setup.py':
             return True
         else:
-            return real_os_path_exists(path)
+            return real_path_exists(path)
 
-    monkeypatch.setattr(os.path, 'exists', mock_os_path_exists)
-    monkeypatch.setattr(sys, 'argv', ['cibuildwheel', MOCK_PACKAGE_DIR])
+    monkeypatch.setattr(Path, 'exists', mock_path_exists)
+    monkeypatch.setattr(sys, 'argv', ['cibuildwheel', str(MOCK_PACKAGE_DIR)])
 
 
 @pytest.fixture(params=['linux', 'macos', 'windows'])

unit_test/main_tests/main_options_test.py

@@ -1,5 +1,6 @@
 import sys
 from fnmatch import fnmatch
+from pathlib import Path
 
 import pytest
 
@@ -12,9 +13,9 @@ from cibuildwheel.util import BuildSelector
 
 
 def test_output_dir(platform, intercepted_build_args, monkeypatch):
-    OUTPUT_DIR = 'some_output_dir'
+    OUTPUT_DIR = Path('some_output_dir')
 
-    monkeypatch.setenv('CIBW_OUTPUT_DIR', OUTPUT_DIR)
+    monkeypatch.setenv('CIBW_OUTPUT_DIR', str(OUTPUT_DIR))
 
     main()
 
@@ -24,14 +25,14 @@ def test_output_dir(platform, intercepted_build_args, monkeypatch):
 def test_output_dir_default(platform, intercepted_build_args, monkeypatch):
     main()
 
-    assert intercepted_build_args.args[0].output_dir == 'wheelhouse'
+    assert intercepted_build_args.args[0].output_dir == Path('wheelhouse')
 
 
 @pytest.mark.parametrize('also_set_environment', [False, True])
 def test_output_dir_argument(also_set_environment, platform, intercepted_build_args, monkeypatch):
-    OUTPUT_DIR = 'some_output_dir'
+    OUTPUT_DIR = Path('some_output_dir')
 
-    monkeypatch.setattr(sys, 'argv', sys.argv + ['--output-dir', OUTPUT_DIR])
+    monkeypatch.setattr(sys, 'argv', sys.argv + ['--output-dir', str(OUTPUT_DIR)])
     if also_set_environment:
         monkeypatch.setenv('CIBW_OUTPUT_DIR', 'not_this_output_dir')
 
@@ -232,3 +233,21 @@ def test_build_selector_migrations(intercepted_build_args, monkeypatch, option_n
         assert intercepted_build_selector.build_patterns == build_selector_patterns
     else:
         assert intercepted_build_selector.skip_patterns == build_selector_patterns
+
+
+@pytest.mark.parametrize('before_all', ["", None, 'test text'])
+@pytest.mark.parametrize('platform_specific', [False, True])
+def test_before_all(before_all, platform_specific, platform, intercepted_build_args, monkeypatch):
+    if before_all is not None:
+        if platform_specific:
+            monkeypatch.setenv('CIBW_BEFORE_ALL_' + platform.upper(), before_all)
+            monkeypatch.setenv('CIBW_BEFORE_ALL', 'overwritten')
+        else:
+            monkeypatch.setenv('CIBW_BEFORE_ALL', before_all)
+
+    main()
+
+    if before_all is None:
+        before_all = ""
+
+    assert intercepted_build_args.args[0].before_all == before_all