work around cibuildwheel not outputting pip-freeze

.github/workflows/build-wheels.yml

@@ -35,6 +35,8 @@ jobs:
         with:
           platforms: all
 
+      - run: mkdir pip-freeze
+
       - name: Build wheels
         uses: pypa/cibuildwheel@v2.12.0
         env:
@@ -55,6 +57,8 @@ jobs:
           name: wheels-${{ matrix.os }}
           path: wheelhouse/*.whl
 
+      - run: tail -n +1 pip-freeze/*
+
   test:
     name: Test wheel for ${{ matrix.os }} Python ${{ matrix.python }}
     needs: build_wheels

.github/workflows/pipfreezedammit.py

@@ -2,6 +2,12 @@
 
 Implemented as a Python script because we need it to work on Windows, etc.
 """
+import os
 import subprocess
 import sys
-subprocess.call([sys.executable, '-m', 'pip', 'freeze'], stdout=sys.stderr)
+
+pythonversion = f'{sys.version_info.major}.{sys.version_info.minor}.{sys.version_info.micro}'
+
+os.makedirs('pip-freeze', exist_ok=True)
+with open(f'pip-freeze/{pythonversion}.txt', 'wt') as fout:
+    subprocess.call([sys.executable, '-m', 'pip', 'freeze'], stdout=fout)