Is there a way to undelete GitHub issue labels?

Question

I accidentally deleted an issues label in GitHub that was labelling several hundred issues. Is there a way to either undelete the label or at least find out which issues had previously been marked with the label?

What happened was that I couldn't see an assigned issue but I knew there was a filter. I thought "Manage labels" might be a likely thing to try so I pressed it. Having pressed it all the numbers went away so I thought, "hey if I click the checkbox besides the bug label then surely I'll be able to see all the bugs."

Except it wasn't a checkbox, it was a small circle around an x for delete. So now I've unmarked all our bugs.

Any ideas how we can restore those labels without having a day long meeting prioritizing our issues again?

Edit: Looks like we got lucky and everything should either be labelled as bug or enhancement. I'll be spending sometime this weekend poking the github api to create a script to add a bug label to everything that isn't an enhancement. At least that's more fun than sitting in a meeting. Thanks for the lesson even if it could have been very painful.

Answer 1

There is no way to undelete issue labels. Once gone, it's gone.

If you had exported a backup of the issues before removing the label(s) then you might be able to go back and reference that to find out which issues had what labels.

Answer 2

In case the deletion was done recently, one can use the Events endpoint of the GitHub REST API v3.

Look for the labels object and the content name. Then you will find the event and the context where the label was deleted. You can then restore it manually or using the API.

(My own deletion was too long ago, no way to recover it)