Spent a while the other day trying to figure out what to use for a Git Diff and Git Merge tool.
Settled on Kdiff3. With this install approach:
brew cask install https://raw.githubusercontent.com/Homebrew/homebrew-cask/6a96e5ea44803e52a43c0c89242390f75d1581ab/Casks/kdiff3.rb
tool = kdiff3
$ git mergetool brings up a useful dialogue.
I had tried Beyond Compare as well as Meld, but neither worked.
I got into it because I was checking out a couple of approaches to updating Trellis for a particular project: