title: Can not undo xcode changes after building
body: <p>Simple but annoying bug, I can't undo my changes once I run my project. Before running I can undo (command + z), but after running I get <a href="https://www.youtube.com/watch?v=8rz44o_gGpE" rel="nofollow noreferrer">mac error sound</a> when I try to undo.</p>
  <p>I'm using xcode 12.2 but it was happening in other versions too.
  I deleted user data, cleaned build folders but no luck.</p>
  <p>What could it be?</p>
  <p>I am using macbook pro 2019 os version is catalina 10.15.7</p>