While trying to install a MSSQL client for terminal on Mac OSX, i found sqsh, but here starts my problems:

How sqsh don't have a brew formula, only two pull requests i think: Why not install trought git PR

After do this, i tried to use sqsh without success e giveup. But not uninstall then on that time.

Someday, when i try to update my brew problem on tap_migrations.json was showed.

Solving the problem

go to brew repo folder cd $(brew --repo) and then find the directory of the tap_migrations with problem. In my case was /usr/local/Homebrew/Library/Taps/homebrew/homebrew-core

then: git checkout origin/master that will show you are 'detached HEAD', but is ok. after run these commands: git branch -D master git fetch origin master git checkout master

And my brew update has returned to work.