[Dev][CI] Extra labels are confusing

[pitrou]

Describe the bug, including details regarding any error messages, version, and platform.

When you add an Extra label for CI, sometimes it gets later removed by a bot. It's not obvious why or when this happens.

Component(s)

Developer Tools, Continuous Integration

[pitrou]

@kou

[kou]

Could you share a sample PR that the problem happened?

[kou]

#50125 (comment) ?

[kou]

@raulcd It seems that

arrow/dev/archery/archery/bot.py

Lines 214 to 216 in 9265a71

	def set_state(self, state):
	"""Sets the State label to the PR."""
	self.pull.add_to_labels(state.value)

that uses https://docs.github.com/en/rest/issues/labels?apiVersion=2026-03-10#add-labels-to-an-issue may remove existing labels when multiple label add requires are processed at once. (I think that it's a bug of GitHub...)

Are we using the "awaiting ..." labels? If we don't use the "awaiting ..." labels, how about removing them? If we remove them, we can avoid this timing sensitive problem.

[pitrou]

I've just used the "Add labels to an issue" API as instructed here to add the Java label to this issue, it didn't remove other labels.

[pitrou]

Note that "Add labels to an issue" uses POST while "Set labels for an issue" uses PUT.

[pitrou]

The GHA-based issue bot uses setLabels instead of addLabels or removeLabel and that might be the issue.

[kou]

#50125 (comment) is a problem case, right?

It's a PR. Our issue bot isn't executed for PR:

arrow/.github/workflows/issue_bot.yml

Lines 20 to 23 in 4e25461

	on:
	issues:
	types:
	- opened

#50125 (comment) (you added CI: Extra: C++ and CI: Extra: R) happened on 2026-06-08T14:02:30Z and
#50125 (comment) (Archery added awaiting review and removed CI: Extra: C++) happened on 2026-06-08T14:02:40Z.

I think that this timeline is related...

[pitrou]

#50125 (comment) is a problem case, right?

Yes. It happens to me often actually.

It's a PR. Our issue bot isn't executed for PR:

Hmm. I see.

I think that this timeline is related...

It is. But it's weird because add_labels is not supposed to remove existing labels...

[pitrou]

I think the problem is that we're using https://github.com/actions/labeler for PRs which uses setLabels.

Another project had the same problem with it: flutter/flutter#128440

[pitrou]

Also see actions/labeler#763 . They claim the issue is fixed but I don't understand how.