Remove get-pip and use ensurepip instead

cibuildwheel/macos.py

@@ -19,7 +19,6 @@ from .util import (
     NonPlatformWheelError,
     download,
     get_build_verbosity_extra_flags,
-    get_pip_script,
     install_certifi_script,
     prepare_command,
     read_python_configs,
@@ -232,8 +231,18 @@ def setup_python(
         )
         sys.exit(1)
 
-    # install pip & wheel
-    call(["python", get_pip_script, *dependency_constraint_flags], env=env, cwd="/tmp")
+    # install pip
+    call(
+        ["python", "-m", "ensurepip", "--default-pip"],
+        env=env,
+        cwd="/tmp",
+    )
+    # ensure we have the version that matches our constraints
+    call(
+        ["python", "-m", "pip", "install", "--upgrade", "pip", *dependency_constraint_flags],
+        env=env,
+        cwd="/tmp",
+    )
     assert (installation_bin_path / "pip").exists()
     call(["which", "pip"], env=env)
     call(["pip", "--version"], env=env)

cibuildwheel/util.py

@@ -24,7 +24,6 @@ from .typing import PathOrStr, PlatformName
 
 resources_dir = Path(__file__).parent / "resources"
 
-get_pip_script = resources_dir / "get-pip.py"
 install_certifi_script = resources_dir / "install_certifi.py"
 
 

cibuildwheel/windows.py

@@ -17,7 +17,6 @@ from .util import (
     NonPlatformWheelError,
     download,
     get_build_verbosity_extra_flags,
-    get_pip_script,
     prepare_command,
     read_python_configs,
 )
@@ -176,7 +175,7 @@ def setup_python(
 
     # make sure pip is installed
     if not (installation_path / "Scripts" / "pip.exe").exists():
-        call(["python", get_pip_script, *dependency_constraint_flags], env=env, cwd="C:\\cibw")
+        call(["python", "-m", "ensurepip", "--default-pip"], env=env, cwd="C:\\cibw")
     assert (installation_path / "Scripts" / "pip.exe").exists()
     where_pip = (
         subprocess.run(