How to only add label, not remove when PR is opened?

[pllim]

I have a labeler action set up for when PR is opened, using all your default settings. The labeler YAML is set up as such (relevant parts listed below):

Docs:
  - docs/*

coordinates:
  - '**/coordinates/**/*'

When astropy/astropy#11023 was opened, the only file changed was docs/coordinates/apply_space_motion.rst. By the labeler logic, it should apply Docs and coordinates.

However, the PR author already manually applied Docs label at creation time. As a result, the labeler ended up removing the Docs label. Is this a bug? How do I tell it to simply no-op when a label that should be applied is already there?

Hope you can help and thanks for such a useful action!

[pllim]

Strangely enough, accidental removal did not happen for astropy/astropy#11028 when the file changed was only docs/conf.py and Docs label was also applied manually when PR was opened.

(The Action ran successfully but it was a no-op, as expected.)

[makecir]

There hasn't been much progress in the conversation, but I also want to solve this problem.
By removing the manually attached tags, the benefits gained by labelar are diminished.

[ericdallo]

Any news here?

[adam-azarchs]

It looks like the problem is

labeler/src/labeler.ts

Line 18 in 5906282

const syncLabels = !!core.getInput("sync-labels", { required: false });

which is not correct because the default value is "false", and !!"false" == true.

[adam-azarchs]

Confirmed, you can work around this bug by setting

sync-labels: ''

in your workflow.