Emacs support Magnet

If you’re using homebrew, you’d normally install the GUI Emacs application via

brew cask install emacs

The problem is that this installs the standard GNU Emacs leveraging some basic Cocoa GUI, which results in the Magnet application not being able to snap Emacs to any of its grids. If you look at the Magnet dropdown with Emacs focused, all of the options will be greyed out.

As described in this reddit post, there is an Emacs distribution designed specifically for Mac OS X that adds additional features through a Carbon port (over Cocoa from default homebrew).

Installing this version can be done via

brew cask install railwaycat/emacsmacport/emacs-mac

As of writing this note, Emacs 26.3 is installed and works well with Magnet 2.4.5 on Mac OS X 10.15.3.