XDG_RUNTIME_DIR on a system with no "logins"

[Guillermo Rodriguez]

Hi all,

Weston requires XDG_RUNTIME_DIR to exist. The specification for this
(https://specifications.freedesktop.org/basedir-spec/latest/ar01s03.html)
says:

===
$XDG_RUNTIME_DIR defines the base directory relative to which
user-specific non-essential runtime files and other file objects (such
as sockets, named pipes, ...) should be stored. The directory MUST be
owned by the user, and he MUST be the only one having read and write
access to it. Its Unix access mode MUST be 0700.

The lifetime of the directory MUST be bound to the user being logged
in. It MUST be created when the user first logs in and if the user
fully logs out the directory MUST be removed. If the user logs in more
than once he should get pointed to the same directory, and it is
mandatory that the directory continues to exist from his first login
to his last logout on the system, and not removed in between. Files in
the directory MUST not survive reboot or a full logout/login cycle.
===

But how is this done for a system where normally no users "log in",
e.g. a fixed-function embedded system with a graphical user interface?

Best,

Guillermo Rodriguez Garcia
guille.rodriguez at gmail.com