This service dynamically creates the directory
specified in the environment variable
XDG_RUNTIME_DIR.
Starting this service creates the directory and sets the proper permissions, stopping it deletes it.
It is recommended to set
XDG_RUNTIME_DIR
to the
@USER@/@USERTREE@/xdg-runtime-dir
subdirectory of the
user runtime directory.
This allows to follow the
XDG Base Directory Specification.
If more than one
user supervision tree
per user is used to have multiple
sessions
with a distinct UI server, audio server, etc.
It makes sense for each session to have its own,
distinct xdg-runtime-dir,
since it is often used for sockets and temporary files
of said UI server, audio server, etc.
Setting
XDG_RUNTIME_DIR
as described above, allows for this.
Note, however, that this deviates from the
XDG Base Directory Specification.
All user services writing to or reading from
XDG_RUNTIME_DIR
should depend on this service.