On 5 Oct 2018, at 13:37, jason wrote:

Great. I have also been trying to track down the crash in NSOutlineView
that I see via -[FSItem isEqual:]!

You saw this with Xcode 10? I have not yet tested for the issue with Xcode 10 myself, but if you saw it on Mojave, then that saves me the trouble.

I did go through basically removing all features of the file browser and yet still had the crash.

I’ve reached a point where rewriting the involved code is probably the most feasible way to try and fix this :(