I'm not 100 percent sure in this instance, but running Desktop GUI commands won't work when you launch things non-interactively from a script not attached to a terminal. This has nothing to do with udev, just try it from a bash script. They have to be run from the right context.

Hi @thomas.bucaioni ,

It seems SYSTEMD_WANTS is intended for other stuff. From the udev(7) man page:

In order to activate long-running processes from udev rules,
provide a service unit and pull it in from a udev device
using the SYSTEMD_WANTS device property. See
systemd.device(5) for details.

Perhaps you can try with the RUN key, as shown in the man page:

RUN{type}
Specify a program to be executed after processing of all the
rules for the event. With "+=", this invocation is added to
the list, and with "=" or ":=", it replaces any previous
contents of the list. Please note that both "program" and
"builtin" types described below share a common list, so
clearing the list with ":=" and "=" affects both types.

       type may be:
 
       "program"
           Execute an external program specified as the assigned
           value. If no absolute path is given, the program is
           expected to live in /usr/lib/udev; otherwise, the
           absolute path must be specified.
 
           This is the default if no type is specified.

I understand you are playing around with udev, because this doesn't seem to be a real case example.

Regards,
Luis.