The "Pull Request Labeler" workflow read the full label set of a pull
request and wrote it back with setLabels(), which is a full replace. Other
workflows label the same pull request at the same time: claude-review.yml
adds the claude-review label on the pull_request_target "opened" event,
which is the very same event that starts the labeler. Whenever that add
landed between the labeler's listLabelsOnIssue() and its setLabels(), the
label was dropped again and the review never ran.
Only ever add or remove the individual labels the labeler owns, so
concurrent changes by other workflows survive. removeLabel() returns 404
when the label is already gone, which is exactly what a racing run causes,
so swallow that status.
Daan De Meyer
a3335922ce