[n4r9]

This only removes references to remote branches. See e.g. [0]. The command in OP operates on local branches.

[0] https://stackoverflow.com/questions/20106712/what-are-the-di...

[henshao]

Just for anyone else following along..you're right. Here it is.

    git fetch -p && git branch -vv | awk '/: gone]/{print $1}' | xargs git branch -d