generate-srcinfo: use native Python and git

Should make things a bit faster, and more reliable.

.github/workflows/generate-srcinfo.yml

@@ -20,19 +20,27 @@ jobs:
         with:
           fetch-depth: 0
 
+      - uses: actions/setup-python@v2
+        with:
+          python-version: '3.9'
+
       - uses: msys2/setup-msys2@v2
         with:
           msystem: MSYS
-          install: python git binutils
+          install: binutils
           update: true
 
-      - run: |
+      - shell: msys2 {0}
+        run: |
           # XXX: linting PKGBUILDs takes a loooong time, this skips it
           sed -i s/^lint_pkgbuild/#lint_pkgbuild/g /usr/bin/makepkg
           # XXX: we don't need the toolchains for --printsrcinfo, but makepkg-mingw complains if gcc doesn't exist
-          touch /mingw64/bin/gcc.exe /mingw32/bin/gcc.exe /ucrt64/bin/gcc.exe /clang64/bin/clang.exe /clang32/bin/clang.exe
+          touch /mingw64/bin/gcc.exe /mingw32/bin/gcc.exe /ucrt64/bin/gcc.exe /clang64/bin/clang.exe /clang32/bin/clang.exe /clangarm64/bin/clang.exe
           curl --fail -L --retry 5 -o srcinfo.json "https://github.com/$GITHUB_REPOSITORY/releases/download/srcinfo-cache/srcinfo.json"
-          python -u .ci/ci-generate-srcinfo.py --time-limit 19800 mingw . srcinfo.json
+
+      - run: |
+          $MSYS2_ROOT=(msys2 -c 'cygpath -w /')
+          python -u .ci/ci-generate-srcinfo.py --time-limit 19800 mingw "$MSYS2_ROOT" . srcinfo.json
 
       - uses: actions/upload-artifact@v2
         with: