Fixing Rosetta 2 on macOS

Useful tip from r/kayatiger¹

I was having the same problem after upgrading macOS I was no longer able to launch Intel apps. Couldn’t reinstall Rosetta through Terminal or via the Rosetta 2 upgrade.app. Even tried booting into recovery and safe mode as well as reinstalling macOS. Turns out Rosetta had become corrupt and the trick to fixing is to manually remove the Rosetta files then reinstalling Rosetta. Below are the instructions how to do it (originally found here)

1. Obtain a list of files/directories and LaunchAgents with: pkgutil --files com.apple.pkg.RosettaUpdateAuto

2. Save them in a way that you can access them in the recovery

3. Boot into recovery

4. Open terminal in recovery (btw to load recovery on M1 macs you long press the power button instead of holding CMD+R)

5. Run csrutil disable and confirm (temporary disable SIP)

6. Reboot

7. Delete the files listed at step 1 (in my case it was enough to delete /Library/Apple/usr/share/rosetta and /Library/Apple/usr/libexec)

8. Reboot back to recovery terminal

9. Run csrutil enable and confirm

Reinstall Rosetta!