How do you remove an invalid remote branch reference from Git?

In my current repo I have the following output:

$ git branch -a
* master
  remotes/origin/master
  remotes/public/master

I want to delete remotes/public/master from the branch list:

$ git branch -d remotes/public/master
error: branch 'remotes/public/master' not found.

Also, the output of git remote is strange, since it does not list public:

$ git remote show 
origin

How can I delete 'remotes/public/master' from the branch list?

Update, tried the git push command:

$ git push public :master
fatal: 'public' does not appear to be a git repository
fatal: The remote end hung up unexpectedly

You might be needing a cleanup:

git gc --prune=now

or you might be needing a prune:

git remote prune public

prune

Deletes all stale tracking branches under <name>. These stale branches have already been removed from the remote repository referenced by <name>, but are still locally available in "remotes/<name>".

With --dry-run option, report what branches will be pruned, but do no actually prune them.

However, it appears these should have been cleaned up earlier with

git remote rm public 

rm

Remove the remote named <name>. All remote tracking branches and configuration settings for the remote are removed.

So it might be you hand-edited your config file and this did not occur, or you have privilege problems.

Maybe run that again and see what happens.

Advice Context

If you take a look in the revision logs, you'll note I suggested more "correct" techniques, which for whatever reason didn't want to work on their repository.

I suspected the OP had done something that left their tree in an inconsistent state that caused it to behave a bit strangely, and git gc was required to fix up the left behind cruft.

Usually git branch -rd origin/badbranch is sufficient for nuking a local tracking branch , or git push origin :badbranch for nuking a remote branch, and usually you will never need to call git gc

All you need to do is

git fetch -p

It'll remove all your local branches which are remotely deleted.

If you are on git 1.8.5+ you can set this automatically

git config fetch.prune true

or

git config --global fetch.prune true

git push public :master

This would delete the remote branch named master as Kent Fredric has pointed out.

To list remote-tracking branches:

git branch -r

To delete a remote-tracking branch:

git branch -rd public/master

All you need to do is

$ git branch -rd origin/whatever 

It's that simple. There is no reason to call a gc here.

git gc --prune=now is not what you want.

git remote prune public

or git remote prune origin # if thats the the remote source

is what you want