If it's public code, a link to a branch with the issue can still be useful. Looking at the compiler internals you can get a better sense on how to minimize the issue. That being said, not having a minimised repro lowers the chance of it getting addressed quickly.
Even if you have already figured out how to deal with it, your future colleagues might not, and by improving the diagnostic you would also be getting that time manually commenting code back.
Even if you have already figured out how to deal with it, your future colleagues might not, and by improving the diagnostic you would also be getting that time manually commenting code back.