I have been seeing something similar on Catalina (10.15) with Xcode 11.3. My project built without errors but when I changed the containing folder name, suddenly I had 34 errors, 34 of which were deprecation warnings.

I found numerous other complaints about the same issue and the apparently related issue that when starting Xcode, it would begin to index the text and never finish. Several users reported that restarting their system cleared up the problem https://stackoverflow.com/questions/50015033/indexing-text-on-xcode, so I tried it and it worked for me.

I'm having the same problem with Xcode 11.3. I finally got my project built without errors or warnings. I made a copy of the project directory, and my attempt to build the copied project seems to be hanging while displaying the "Using build description from memory" message. Previous copies of earlier stages, as I was eliminating errors, had no such problems, a copy would build with the same set of errors and warnings as the original project. The fact that it's saying "from memory" concerns me. I've tried stopping Xcode and restarting it. I'm wondering if it might take rebooting to clear this "memory" issue. That's a pain to do, with all the stuff I have open, but if I don't find another solution, I'll try it. I'll try to report back here if I have any success.

I'm trying to change the name for a separate copy of TextEdit and I cannot find either CBBundleDisplayName, CFBundleDisplayName, or CFBundleName in the Contents of the TextEdit copy.app. The only .plist file that I can find inside TextEdit copy.app/Contents which contains "TextEdit" is /Applications/TextEdit copy.app/Contents/Resources/TextEdit-Entitlements.plist which contains the key: <key>com.apple.application-identifier</key> <string>com.apple.TextEdit</string> However, it doesn't seem likely (but I'm guessing) that the Main Menu would take it's app name from this key. Any other ideas on how to make this work with TextEdit on Catalina?