Interesting! I have a mac here to test. Will look into it and see if we can fix this soon!
-Alex
Sure. Basically in the past the issue I've had is I do a MacOS build for release in Unity, and the binary might even run locally but when I zip it up and try it on another Mac, it wont run, it might even not recognize it as open-able.
MacOS "Applications" are just folders with specific structures & manifests in the right places, the important path is: "MyApp.app/Contents/MacOS/MyApp". I've noticed that sometimes the filesystem "+x" flag, which denotes that this file is executable/runnable, is either not set, or set in a very limited way. In the past I've had luck issuing a command like: "chmod uog+x MyApp.app/Contents/MacOS/MyApp", which is basically saying "change permissions on this file, Users (u), Others (o), and Group (g) will gain (+) the executable flag (x).
Because the bundle isn't signed, it will still require users to right click it and select "Open", and then they can accept the warning dialog about un-trusted files and open Unity.