From the man page for git branch
:
Delete a branch. The branch must be fully merged in its upstream branch, or in HEAD if no upstream was set with --track or --set-upstream.
$ git branch -d skin
warning: deleting branch 'skin' that has been merged to
'refs/remotes/origin/skin', but not yet merged to HEAD.
Deleted branch skin (was 1f97b5b).
$ git remote -v
origin git@github.com:me/Banana.git (fetch)
origin git@github.com:me/Banana.git (push)
upstream git@github.com:others/Banana.git (fetch)
upstream git@github.com:others/Banana.git (push)
The skin branch was actually removed (locally) but I was trying to understand what the warning message means. Note the skin branch was still available at origin and upstream, as expected.