I finally got around to upgrading my OS X installation from Mojave to High Sierra – my OS update schedule is usually based on the old pilot wisdom of “don’t fly the A model of anything”. As part of the upgrade, I ended up reinstalling all homebrew packages including Emacs to make sure I was all up to date. That proved to be a big mistake as I suddenly had a GUI-less Emacs. Of course I found the post on Irreal about the Emacs homebrew package being broken on Mojave after, well, I noticed that my Emacs GUI wasn’t working. Oops.
A bit more poking around the Internet brought me to the homebrew cask for the Emacs Mac Port. As the screenshot below shows, it works with a UI on Mojave, so if you’re looking for an alternative to the regular Emacs port, this one seems to be fine, at least based on a quick “test drive”.

Time to make sure that the installed packages are also working as it doesn’t seem to recognise org2blog and I ended up having to write this post in the WordPress editor. Can’t have that.
Brew removed all options from their supported formulae to reduce their support load. Unfortunately enabling the GUI in Mac Emacs needs an option, thus the GUI-less build. There’s a brew tap that brings all of the options back which is available at:
https://github.com/daviderestivo/homebrew-emacs-head
Interesting, I wasn’t aware of that. I did try the regular –HEAD build for the emacs formula and that resulted in no UI, either.
I’ll have a look at the cask you mentioned, although so far the cask I mentioned above also seems to work.