I really don't want to have to wipe my entire Mac and reinstall macOS but I think I might have to because the Mac App Store is very broken. This all started when my computer went to sleep during a MAS installation many months ago. After working with Apple support I managed to wipe out the MAS cache, download storage, etc.

The issue is that now future downloads from the MAS of iMovie break on this step:

2022-10-16 16:36:36+13 bruce-wayne root[2777]: Running Install Scripts . . .
2022-10-16 16:36:36+13 bruce-wayne root[2779]: Begin script: iMovie_PP
2022-10-16 16:36:36+13 bruce-wayne root[2783]: End script: iMovie_PP
2022-10-16 16:36:36+13 bruce-wayne root[2784]: Begin script: updateHelpPost
2022-10-16 16:36:36+13 bruce-wayne package_script_service[2770]: postinstall: No matching processes were found
2022-10-16 16:36:37+13 bruce-wayne package_script_service[2770]: postinstall: shell-init: error retrieving current directory: getcwd: cannot access parent directories: Permission denied
2022-10-16 16:36:37+13 bruce-wayne package_script_service[2770]: postinstall: Error: The current working directory doesn't exist, cannot proceed.

(from tail -f /var/log/install.log)

The install is stuck there because it cannot install the help data. I've tried deleting everything in the sandbox dir, booting into safe mode, deleting the iMovie .app file and rebooting, and it all fails.

The only remaining thing I can think of is to wipe my mac and start over. Does anyone have any other ideas?