DEBUG: verify that the newly-patched MSYS2 runtime works around the W…

…indows/ARM64 deadlocks

I updated git-for-windows/msys2-runtime#73 to
build the newest iteration of the dead-lock workaround, which worked
100% in my tests.

Let's verify that it works around the issues in `update-via-pacman.ps1`,
too.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

.github/workflows/sync.yml

@@ -1,13 +1,7 @@
 name: sync
 
 on:
-  schedule:
-    - cron: "57 2 * * *"
-  workflow_dispatch:
-    inputs:
-      debug_with_ssh_key:
-        description: 'Public SSH key to use to debug failures'
-        required: false
+  push:
 
 env:
   GIT_CONFIG_PARAMETERS: "'user.name=Git for Windows Build Agent' 'user.email=ci@git-for-windows.build' 'windows.sdk64.path=${{ github.workspace }}' 'windows.sdk32.path=' 'http.sslbackend=schannel' 'core.autocrlf=false' 'checkout.workers=16'"
@@ -25,10 +19,52 @@ jobs:
         with:
           persist-credentials: true
           token: ${{ secrets.PUSH_TOKEN }}
+      - name: use git-sdk-arm64's Bash and Git for Windows' git.exe
+        run: "usr\\bin\\bash.exe -lc 'cygpath -aw /usr/bin >>$GITHUB_PATH && cygpath -aw /c/Program\\ Files/Git/cmd/ >>$GITHUB_PATH'"
+      - name: download patched MSYS2 runtime
+        id: download
+        shell: bash
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: |
+          # Only do this if `pacman` is prevented from being upgraded
+          grep '^ *IgnorePkg *= *pacman' etc/pacman.conf || exit 0
+
+          pacman -S --noconfirm mingw-w64-clang-aarch64-github-cli &&
+          git add -A &&
+          git commit -sm 'TO-DROP: install GitHub CLI' || exit 1
+
+          sha="$(gh api repos/git-for-windows/msys2-runtime/pulls/73 \
+               --jq '.head.sha')" &&
+          check_run_url="$(gh api repos/git-for-windows/msys2-runtime/commits/$sha/check-runs \
+                         --jq '.check_runs[] | select(.name=="MSYS") | .url')" &&
+          workflow_job_url="$(gh api "${check_run_url#https://api.github.com/}" --jq '.details_url')" &&
+          workflow_run_url="${workflow_job_url%/job/*}" &&
+          artifacts_url="$(gh api "repos/${workflow_run_url#https://github.com/}" --jq '.artifacts_url')" &&
+          zip_url="$(gh api "${artifacts_url#https://api.github.com/}" --jq '.artifacts[].archive_download_url')" &&
+          curl -H "Authorization: token ${{secrets.GITHUB_TOKEN}}" -#sLo /tmp/install.zip "$zip_url" &&
+          unzip /tmp/install.zip
+      - name: commit MSYS2 runtime
+        shell: bash
+        run: |
+          # Give the `/etc/profile.d/` scripts a chance to set things up
+          bash -lc 'uname -a' &&
+
+          git add -A &&
+          git commit -m 'Install patches MSYS2 runtime' &&
+          sed -i 's/^*\(IgnorePkg *=\).*/# &/' etc/pacman.conf &&
+          git commit -m 'Allow `pacman` to be upgraded again' \
+            -m 'It had been overridden with a version that does not deadlock on Windows/ARM64, but now an MSYS2 runtime has been installed that prevents that deadlock in a much better way' \
+            etc/pacman.conf &&
+          git push origin HEAD
       - name: Update all Pacman packages
         shell: pwsh
         run: |
           & .\update-via-pacman.ps1
+      - name: Update all Pacman packages again, for good measure
+        shell: pwsh
+        run: |
+          & .\update-via-pacman.ps1
       - name: use git-sdk-arm64's Bash and Git for Windows' git.exe
         run: "usr\\bin\\bash.exe -lc 'cygpath -aw /usr/bin >>$GITHUB_PATH && cygpath -aw /c/Program\ Files/Git/cmd/ >>$GITHUB_PATH'"
       - name: deal with large DLL files