ci: labeler: avoid checking out fork codebase

Refactor the PR labeler workflow to checkout the base repository ref
instead of the pull request head ref from forks, resolving checkout
errors inside the pull_request_target context.

Signed-off-by: Josef Schlehofer <redacted>

diff --git a/.github/workflows/labeler.yml b/.github/workflows/labeler.yml
index b7f9200aebaeec0f973b2f541182db8d135a96c3..a22139fafd5657a2849149920ef254d5523c53ca 100644 (file)
--- a/.github/workflows/labeler.yml
+++ b/.github/workflows/labeler.yml
@@ -16,26 +16,26 @@ jobs:
           repo-token: '${{ secrets.GITHUB_TOKEN }}'
           sync-labels: true
 
-      - name: Checkout PR code
+      - name: Checkout base code
         uses: actions/checkout@v7
         with:
-          ref: ${{ github.event.pull_request.head.sha }}
+          ref: ${{ github.event.pull_request.base.sha }}
           fetch-depth: 0
 
-      - name: Fetch base
-        run: git fetch origin ${{ github.event.pull_request.base.sha }}
+      - name: Fetch PR commits
+        run: git fetch origin pull/${{ github.event.pull_request.number }}/head
 
       - name: Check for PKG_VERSION changes
         id: check_version
         # Check for new packages (any Makefile with status 'A' - Added)
         # Check for dropped packages (any Makefile with status 'D' - Deleted)
         run: |
-          if git diff --name-only --diff-filter=A "${{ github.event.pull_request.base.sha }}"...HEAD -- '**/Makefile' | grep -q .; then
+          if git diff --name-only --diff-filter=A HEAD...FETCH_HEAD -- '**/Makefile' | grep -q .; then
             echo "New package detected."
             echo "new_package=true" >> $GITHUB_OUTPUT
           fi
 
-          if git diff --name-only --diff-filter=D "${{ github.event.pull_request.base.sha }}"...HEAD -- '**/Makefile' | grep -q .; then
+          if git diff --name-only --diff-filter=D HEAD...FETCH_HEAD -- '**/Makefile' | grep -q .; then
             echo "Dropped package detected."
             echo "dropped_package=true" >> $GITHUB_OUTPUT
           fi