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

You say that you have:

also checked .git/refs/heads and there's no reference to t_1140

... which is very surprising. I can only see how this error would occur if the file .git/refs/heads/t_1140 exists. Is it possible you were mistaken about this?

Correction: Charles Bailey points out below that the refs might be packed, in which case there is no corresponding file in .git/refs/heads