Launching a program from the start menu of the Mate desktop (as provided
by the ‘mate-desktop-service-type’) currently (commit: 41ee209) fails.
The error message complains about a missing ‘gio-launch-desktop’ (found
in the “bin” output of ‘glib’).
This can be worked around by adding ‘(list glib "bin")’ to the list of
global packages in the ‘operating-system’ configuration.