Apple - .git-completion.bash producing error on macOS Sierra 10.12.6

I ran into the exact same problem. After some digging, I finally figured out what the root problem is.

They made some major changes to the git-completion.bash script which requires a new feature in git v2.18, --list-cmds. The problem is that none of the package managers have updated to git v2.18 yet.

Most of the instructions out there say to download raw.githubusercontent.com/git/git/master/contrib/completion/git-completion.bash . But that is not necessarily the best option because sometimes you will be downloading a newer git-completion.bash than your version of git supports.

So the solution is to download the git-completion.bash version that matches your git version. Then source it again. In this case:

https://raw.githubusercontent.com/git/git/v2.17.1/contrib/completion/git-completion.bash

Notice that it is referencing v2.17.1 instead of master. Later, when you install git v2.18, then you can switch back to master, or v2.18 tag.

Upgrading the git to the latest version is the simplest solution. https://git-scm.com/download/mac

After that make sure you follow the steps

1. curl https://raw.githubusercontent.com/git/git/master/contrib/completion/git-completion.bash -o ~/.git-completion.bash

2. Add this small command into the .bash_profile file if [ -f ~/.git-completion.bash ]; then . ~/.git-completion.bash fi

Don't build it from source; instead install from MacPorts.

To install git with auto-completion, issue the following command:

 $ sudo port install git +bash_completion

close and reopen your Terminal and git completion should work