Enable CI for windows-2019 (#3168)

Author: abravalheri

.github/workflows/main.yml

@@ -24,8 +24,7 @@ jobs:
         platform:
         - ubuntu-latest
         - macos-latest
-        # disable tests on Windows due to pypa/distutils#118
-        # - windows-latest
+        - windows-2019
         include:
         - platform: ubuntu-latest
           python: "3.10"

setuptools/tests/test_build_meta.py

@@ -18,6 +18,13 @@
 IS_PYPY = '__pypy__' in sys.builtin_module_names
 
 
+pytestmark = pytest.mark.skipif(
+    sys.platform == "win32" and IS_PYPY,
+    reason="The combination of PyPy + Windows + pytest-xdist + ProcessPoolExecutor "
+    "is flaky and problematic"
+)
+
+
 class BuildBackendBase:
     def __init__(self, cwd='.', env={}, backend_name='setuptools.build_meta'):
         self.cwd = cwd