"not writable: Operation not permitted" error not clear when chown not possible

[fviard]

When doing a sync from remote to local, if the uid and gid were preserved, and we are unable to restore them because of insuficient permission, we will get an error that is not clear at all:

Ex.:

WARNING: /home/bnode/tmpdest/prkeep/locale/zu/LC_MESSAGES/mate-polkit.mo not writable: Operation not permitted