Add test failure with descriptive error message when running tests without a {project} placeholder

cibuildwheel/macos.py

@@ -36,6 +36,7 @@ from .util import (
     read_python_configs,
     shell,
     split_config_settings,
+    test_fail_cwd_file,
     unwrap,
     virtualenv,
 )
@@ -563,7 +564,7 @@ def build(options: Options, tmp_path: Path) -> None:
                             "pip", "install", *build_options.test_requires, env=virtualenv_env
                         )
 
-                    # run the tests from $HOME, with an absolute path in the command
+                    # run the tests from a temp dir, 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(
@@ -571,9 +572,12 @@ def build(options: Options, tmp_path: Path) -> None:
                         project=Path(".").resolve(),
                         package=build_options.package_dir.resolve(),
                     )
-                    shell_with_arch(
-                        test_command_prepared, cwd=os.environ["HOME"], env=virtualenv_env
-                    )
+
+                    test_cwd = identifier_tmp_dir / "test_cwd"
+                    test_cwd.mkdir(exist_ok=True)
+                    (test_cwd / "test_fail.py").write_text(test_fail_cwd_file.read_text())
+
+                    shell_with_arch(test_command_prepared, cwd=test_cwd, env=virtualenv_env)
 
             # we're all done here; move it to output (overwrite existing)
             if compatible_wheel is None: