Restoring from Time Machine backup relocates home directories

[db]

On 15 Sep 2017, at 23:47, Ryan Schmidt <ryandesign at macports.org> wrote:
> MacPorts and ports can add users, but MacPorts doesn't remove them. I'm not sure how we could change that. Suppose you install a port that has a user that needs to own some data, such as postresql96-server. You then uninstall the port, which then hypothetically removes the user. Now the databases you created with that port are owned by a userid that doesn't exist anymore. Now you reinstall the port, which creates a postgres user but with a new userid. This creates more work for the user: needing to reassociate files the port needs with the new userid.

Shouldn't MP delete it if no files are owned by that user? In any case, it could notify during installation that a user was created and upon uninstallation that a user still owns files (and which) or not, and if not, it could give the option to delete it.

I searched for files owned by users created by two ports installed not long ago (quagga is still installed, dbus uninstalled) to find the following (just an example of a mess I now realised it's in place and I don't have a clue how it happened).

$ ls -l /Library/Screen\ Savers/Substrate.saver/Contents
total 16
-rw-r--r--@ 1 root    messagebus   692 Apr 12  2010 CodeResources
-rw-r--r--@ 1 root    messagebus  1491 Apr 12  2010 Info.plist
drwxr-xr-x@ 3 quagga  messagebus   102 Apr 12  2010 MacOS
drwxr-xr-x@ 3 quagga  messagebus   102 Apr 12  2010 Resources
drwxr-xr-x@ 3 quagga  messagebus   102 Apr 12  2010 _CodeSignature

AFAIR, I installed that screen saver by dragging and dropping, no installer.

MP could also checked if the UIDs/GIDs are already in use, before a port creates a user/group.