I followed firstly the instructions on this page, but I instead copied it to the 2.7 folder and ran the install instructions from each folder which didn’t work.
The instructions on that page don’t seem correct? Doesn’t seem like it’s a simple matter of just copying the files in to the folder, and what about the part that says install in /Library/Python/2.5/site-packages/ instead of 2.7/2.6?
Then I found instructions on the GitHub, which didn’t work either… since Glyphs can’t find Vanilla
I then deleted everything in these 2.7, 2.6 folders and reinstalled it with the contents of the zip file in a folder that was not inside the Python folder. Now it worked