I used to be able to see source diffs in the editor with Xcode. Now the "Enable Code Review" button doesn't do anything when I click it. I'm running Xcode 13 beta 13A5154h and macOS 11.4 20F71. Can someone help?
I finally figured this out. Open Xcode preferences, go to the Source Control pane, in "Text Editing:" enable "Show Source Control changes". Then the diff view will work again.
I think this setting should be on by default. I spent way too much time trying to figure this out.