Very unimpressed with the so called "fix" for #842145 of just blocking running the script on nfs mount rather than fixing the script to work properly with nfs.
The problem with the script is that it does not ignore the .nfs* files. An explanation of these files is available here: https://unix.stackexchange.com/questions/348315/nfs-mount-device-or-resource-busy I am not a programmer so will not share my crappy attempt at getting the script to work. I will describe a workaround I did and maybe that may help someone come up with their own workaround for system with nfs root (where the nfs server is not running linux). Or even better maybe the package maintainer might adjust the script within usrmerge to work properly with nfs using these ideas. - Starting from bullseye (I rolled back to a snapshot pre-install of usrmerge), downloaded src of usrmerge to get access to the convert-usrmerge script. - modify script to try and get it to ignore/avoid changing any objects with ".nfs000" in its name - run the script so it hopefully completes successfully (In my case it did not fully complete. It made most of the changes but I still had some directories in root such as /lib - probably from mistakes in my code changes) - rebooted nfs client to clear open file handles on nfs which would remove .nfs000* files - ran the original unmodified script which this time completed successfully including converting eg /lib to a symlink. I think this worked as most of the files had moved and symlinks created so there was not much left for it to do except sort out the remaining few moves/symlinks. - installed usrmerge package which this time completed (it detected the merge completed and did not complain about nfs) >From there I expect it should be safe to upgrade to bookworm without usrmerge breaking the upgrade (not tested yet). good luck
