cpp-packaging.yml: install patch.exe via choco on Windows

.github/workflows/cpp-packaging.yml

@@ -425,6 +425,13 @@ jobs:
           fi
           echo "VERBOSE_FLAG=${verbose_flag}" >> $GITHUB_ENV
 
+      - name: Use patch.exe from Git (windows)
+        if: startsWith(matrix.os, 'windows')
+        shell: bash
+        run: |
+          python scripts/gha/setup_patch_from_git_windows.py >> $GITHUB_PATH
+          echo "PATH is now: $PATH"
+
       # Run the build in the host OS default shell since Windows can't handle long path names in bash.
       - name: Build desktop SDK
         run: |

scripts/gha/setup_patch_from_git_windows.py

@@ -0,0 +1,43 @@
+import os
+import pathlib
+import shutil
+import tempfile
+
+from absl import app
+from absl import logging
+
+def main(argv):
+  if len(argv) > 1:
+    raise app.UsageError(f"unexpected argument: {argv[1]}")
+
+  logging.info("Searching for git.exe")
+  git_executable_path_str = shutil.which("git")
+  if not git_executable_path_str:
+    raise Exception("git not found in the PATH")
+  git_executable = pathlib.Path(git_executable_path_str)
+  logging.info("Found: %s", git_executable)
+
+  logging.info("Searching for patch.exe")
+  patch_executable = git_executable.parent / "patch.exe"
+  if not patch_executable.exists():
+    raise Exception(f"file not found: {patch_executable}")
+  logging.info("Found: %s", patch_executable)
+
+  logging.info("Searching for msys-2.0.dll")
+  msys_dll = patch_executable.parent / "msys-2.0.dll"
+  if not msys_dll.exists():
+    raise Exception(f"file not found: {msys_dll}")
+  logging.info("Found %s", msys_dll)
+
+  temp_dir = pathlib.Path(tempfile.mkdtemp("patch"))
+  logging.info("Created temporary directory: %s", temp_dir)
+  logging.info("Copying %s to %s", patch_executable, temp_dir)
+  shutil.copy2(patch_executable, temp_dir)
+  logging.info("Copying %s to %s", msys_dll, temp_dir)
+  shutil.copy2(msys_dll, temp_dir)
+
+  print(str(temp_dir))
+
+
+if __name__ == "__main__":
+  app.run(main)