I tried the workaround and it is insufficient. It works for several hours and then the issue reappears. Reinstalling Xcode again works for a while. I have reinstalled Xcode four times because of this now. I have opened a bug report (FB9811795) and included additional information and TWO sysdiagnose files. The first was created after a clean re-install of Xcode 13.2 from the Apple Developer Website. After less nearly 24 hours the problem resurfaced. The second sysdiagnose file was created right after this. I really hope this helps. Please fix this as quickly as possible.

Installing the version of Xcode from the Apple Developer Website only fixes the problem temporarily. The same “Internal error: missingPackageDescriptionModule.” showed up a few hours after installation. I've re-installed Xcode FIVE times. Filed bug with Feedback Assistant (including sysdiagnose files before and after problem occurs): FB9811795.

You can download 13.1 here: https://developer.apple.com/download/all/ Just scroll down. FWIW: I've reinstalled 13.2 several times now, each time the problem goes away for a while and then returns. If it's not fixed by next week I'm downgrading.