Getting rid of '… does not point to a valid object' for an old git branch

Question

I have a fork of a Git repo and my clone appears to have an issue with an old, no longer existant, branch. I keep seeing this message:

error: refs/heads/t_1140

Answer 1

This fixed it for me:

git push origin :refs/remotes/origin/[branch name]
git push origin :refs/heads/origin/[branch name]

WARNING: this deletes the branch from the server - any changes on that branch that have not been merged to another branch will be lost.