[BUG] Weird spree of "duplicate" labels from github actions

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

There seems to be a weird prevalence of "duplicate" labels recently. I organically came across it in https://github.com/anthropics/claude-code/issues/65880 and https://github.com/anthropics/claude-code/issues/66081 but a search for "label:duplicate" reveals several hundred non-closed issues with this label. The ones I spot-checked all have the same pattern; a Github action added some topical labels (apparently based on the contents of the bug) but also the "duplicate" label without adding a link to which issue is duplicated (and probably there never was one anyway).

What Should Happen?

The Github action should not add the "duplicate" label; or if indeed it finds a duplicate, it should link to it. But even then the normal and intended behavior seems to be to post a comment pointing to possible duplicates and waiting for the user's feedback; this is a separate workflow.

Error Messages/Logs

label:duplicate

Steps to Reproduce

It's not happening all the time, and I don't see any particular reason it triggers on some issue reports and not others. As far as I can tell the repro steps are

1. Report an issue
2. Be unlucky when the Github Action labeling job runs

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

unknown

Claude Code Version

not relevant

Platform

Other

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_