UI unrecoverably freezes constantly on El Capitan

[marcello3d]

Hey there, long time user of GitX, and after updating to El Capitan (clean install), GitX has been failing regularly: spinning pizza wheel of death, forever and ever, even if I wait 10+ minutes, doesn't seem to be using CPU.

It seems to typically happen when I do anything that invokes git (update, commit, push, stage, unstage), though it's random and extremely frustrating!

Let me know what information I can give you to help.

[duetosymmetry]

I can reproduce this—I experience it when committing hunks.

This issue should be marked as Bug. It essentially makes gitx useless.

CC @rowanj