canonicalize_file_name() invocations were replaced by chase_symlinks() in
Decemeber 2016 with PR #4694, so we don't need this mention in the TODO anymore
"systemd-gdb" for attaching to the start-up of any system service in its
natural habitat.
-* replace all canonicalize_file_name() invocations by chase_symlinks(), in
- particulr those where a rootdir is relevant.
-
* maybe introduce gpt auto discovery for /var/tmp?
* maybe add gpt-partition-based user management: each user gets his own