GitHub now support having nested teams: https://github.com/blog/2378-nested-teams-add-depth-to-your-team-structure

But it seems like membership information now doesn't work as expected. In my particular case I had teams Parent and Child, and Bob was part of both Parent and Child and Bill was part of Parent only (so Parent = {Bob, Bill} | Child = {Bob}). I had then Parent as a jenkins group to give access to users.

To switch to nested groups I set Parent as the parent team for Child and removed Bob from Parent, as he is part of it transitively now (so Parent = {Bill, Child = {Bob} }).

Now Bob can't get into Jenkins. I guess that the GitHub API is now not reporting Bob as a member of Parent, I don't know if the API calls changed or if a new API call should be used to check for inherited membership.

I contacted GtiHub support about this too, but maybe the issue here is in Jenkins, so reporting here too.