I’m using UE 4.25.1 came as installation, not from source code. I’m implementing stuff in C++.
I noticed Xcode build indefinite gets stuck sometimes. I found that it is when iOS simulator is open. It sounds like a process from iOS simulator holds on to a resource(?) that the build tool process needs to lock on to.
Anyway, quitting iOS simulator solved my issue. I don’t expect a fix from Epic, but I want to leave a note for what I found.