Trouble setting up git with my GitHub Account error: could not lock config file

Check if you have a .git directory in your home folder and if you don't:

mkdir ~/.git

Solved the problem in my case.

A bit like in "Trouble setting up Tower with my GitHub Account - error: could not lock config file", check how that ~/.gitconfig file has been created.
Ie: with which rights associated to it?

Make also sure your $HOME variable is correctly set when you are executing the git config --global command.