Is there a binary of Scid vs Mac which works on macOS Mojave? I had ScidvsMac 4.19 running on my Mac - ScidvsMac-4.19.dmg from https://sourceforge.net/projects/scidvspc/files/mac/ - but after upgrading to macOS Mojave (10.14.1) it doesn't run - the icon just bounces forever.

I have been trying to use macports compilers to compile the latest source but I am just lost in dependency hell right now because I can't seem to install libgcc7 or libgcc8 properly. I might try to blow everything away and start a fresh install ... but wondering if anyone has overcome these problems?
Your question is pretty old. Did you succeeded to resolve your problem? I am running scidvsmac 4.19 on Mojave without any problem. You may download it here: 

http://scidvspc.sourceforge.net/#toc3

Best greetings 

marek