Git prune to remove reference to master

TLDR: This command will fully get rid of the master branch after you've switched to using main.

git remote prune origin

What I was seeing was git checkout master still referenced the existence of the old branch I had used. I needed to get rid of that old one so that it would be an error.

The switch

We have switched to using the main branch instead of the master branch on all our Github projects.

When you do so, you get this helpful screenshot from Github:

Those instructions typed out:

> git branch -m master main
> git fetch origin
> git branch -u origin/main main

I have also seen this one added:

> git symbolic-ref refs/remotes/origin/HEAD refs/remotes/origin/main

Muscle memory

However, I still had a problem. My fingers kept typing git checkout master when I should now be typing git checkout main.

I would get over that in time, except that it wasn't giving me an error even though this was not a local or remote branch:

> git checkout master
Branch 'master' set up to track remote branch 'master' from 'origin'.
Switched to a new branch 'master'

> git checkout blah
error: pathspec 'blah' did not match any file(s) known to git

I wanted to get the second result: an error. Then my fingers would learn what my heart and head knew was right.

Solution

The solution hint came from running this command:

> git branch -a
* main
  remotes/origin/HEAD -> origin/main
  remotes/origin/any_old_branch
  remotes/origin/blog_config
  remotes/origin/main
  remotes/origin/master

So if I did git checkout any_old_branch that would not error either even though that was not a local or remote branch.

The solution was to run git remote prune origin:

> git remote prune origin
Pruning origin
URL: git@github.com:grouparoo/www.grouparoo.com.git
 * [pruned] origin/any_old_branch
 * [pruned] origin/blog_config
 * [pruned] origin/master

Now it is gone from git branch -a and I get the expected result:

> git checkout master
error: pathspec 'master' did not match any file(s) known to git