PR can be opened during the export

.github/workflows/backup.yml

@@ -23,13 +23,24 @@ jobs:
           sudo apt-get -y install restic
       - name: Trigger backup export
         run: |
+          # needed for sanity check
+          NUMBER=$(gh api \
+            -H "Accept: application/vnd.github+json" \
+            -H "Authorization: Bearer $GH_TOKEN" \
+            -H "X-GitHub-Api-Version: 2022-11-28" repos/$REPO/pulls --jq '.[0].number')
+          TITLE=$(gh api \
+            -H "Accept: application/vnd.github+json" \
+            -H "Authorization: Bearer $GH_TOKEN" \
+            -H "X-GitHub-Api-Version: 2022-11-28" repos/$REPO/pulls --jq '.[0].title')
           ID=$(gh api --method POST /user/migrations \
             --raw-field "repositories[]=$REPO" \
             --field lock_repositories=false \
             --field exclude_git_data=true --jq '.id')
           # define some ENV vars needed below
+          echo "LATEST_PR_NUMBER=$NUMBER" >>$GITHUB_ENV
+          echo "LATEST_PR_TITLE=$TITLE" >>$GITHUB_ENV
           echo "EXPORT_ID=$ID" >>$GITHUB_ENV
-          echo "REPO_NAME=${{ github.event.repository.name }}" >> $GITHUB_ENV
+          echo "REPO_NAME=${{ github.event.repository.name }}" >>$GITHUB_ENV
       - name: Wait until backup is finished
         run: |
           while true; do
@@ -46,12 +57,12 @@ jobs:
             -o "archive.tgz" "$ARCHIVE_URL"
       - name: Sanity check
         run: |
-          TITLE_LATEST_PR=$(gh api \
-            -H "Accept: application/vnd.github+json" \
-            -H "Authorization: Bearer $GH_TOKEN" \
-            -H "X-GitHub-Api-Version: 2022-11-28" repos/$REPO/pulls --jq '.[0].title')
-          zgrep -a -B3 "$TITLE_LATEST_PR" archive.tgz || {
-            echo "Latest PR title not found in archive.tgz"
+          # Make sure that we have the latest PR information
+          # title and corresponding number (from URL)
+          zgrep -a -B3 "$LATEST_PR_TITLE" archive.tgz |
+            grep "\"url\":" |
+            grep -q "https://github.com/$REPO/pull/$LATEST_PR_NUMBER" || {
+            echo "Latest PR not found in archive.tgz"
             exit 1
           }
       - name: Save backup (restic)