Auto merge of #2945 - oli-obk:gha_mk_pr, r=RalfJung

Try running a sync automatically

absolutely no clue if this works, but it happens after the zulip message, so worst case we'll see the failure after the cron job did everything it currently does.

src/tools/miri/.github/workflows/ci.yml

@@ -156,13 +156,13 @@ jobs:
       - name: mark the job as a failure
         run: exit 1
 
-  # Send a Zulip notification when a cron job fails
   cron-fail-notify:
     name: cronjob failure notification
     runs-on: ubuntu-latest
     needs: [build, style]
     if: github.event_name == 'schedule' && (failure() || cancelled())
     steps:
+      # Send a Zulip notification
       - name: Install zulip-send
         run: pip3 install zulip
       - name: Send Zulip notification
@@ -185,3 +185,27 @@ jobs:
           Sincerely,
           The Miri Cronjobs Bot' \
             --user $ZULIP_BOT_EMAIL --api-key $ZULIP_API_TOKEN --site https://rust-lang.zulipchat.com
+      # Attempt to auto-sync with rustc
+      - name: install josh-proxy
+        run: cargo +stable install josh-proxy --git https://github.com/josh-project/josh --tag r22.12.06
+      - name: start josh-proxy
+        run: josh-proxy --local=$HOME/.cache/josh --remote=https://github.com --no-background &
+      - name: setup bot git name and email
+        run: |
+          git config --global user.name 'The Miri Conjob Bot'
+          git config --global user.email 'miri@cron.bot'
+      - name: get changes from rustc
+        run: ./miri rustc-pull
+      - name: format changes (if any)
+        run: |
+          ./miri toolchain
+          ./miri fmt --check || (./miri fmt && git commit -am "fmt")
+      - name: Push changes to a branch
+        run: |
+          git switch -c "rustup$(date -u +%Y-%m)"
+          git push
+      - name: Create Pull Request
+        run: gh pr create -B master --title 'Automatic sync from rustc' --body ''
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+