Accessing gnome utilities via ctwm in Fedora27

Letting off steam!

It's possible that what I've just learnt may be of use to other ctwm users
whose linux distributions change in 'hidden' ways. This wasted a *lot* of
my time!

After upgrading my laptop and desktop machines from Fedora 25 to 27 I was
annoyed to find that items accessing gnome-control-center in .ctwmrc
stopped working, e.g.

  "Gnome Vol"   ! "/usr/bin/gnome-control-center sound &"
  "NET"         ! "/usr/bin/gnome-control-center network &"

did not work.

After struggling for some time to find alternatives, I stumbled across this
bug-report:

    https://www.reddit.com/r/Fedora/comments/7dcc0o/fix_for_blank_gnome_control_center_settings_with/

and learnt that to preserve the old functionality of gnome-control-center,
it is now necessary to define this environment variable:

    XDG_CURRENT_DESKTOP  as  GNOME

E.g., since I've got into the habit of using tcsh as my login shell, I now
have put this in a login script:

     setenv XDG_CURRENT_DESKTOP GNOME

I presume bash users will need to use export ?

The reddit bug-report adds:

     You can edit the desktop entry file at
        /usr/share/applications/gnome-control-center.desktop

I think it's better for individual users, especially on a shared machine,
to make such changes, instead of using a 'central' location, e.g.
    /usr/share/...

Would it be possible for CTWM users to extend the functionality of .ctwmrc
with an environment section, e.g., by analogy with 'Color:'

Something like:

Environment_extensions:
    {
        XDG_CURRENT_DESKTOP GNOME
        PATH ...
    }

so that all commands invoked will from ctwm will have the required
environment-extensions. Restricting $PATH could be useful for 'secure'
environments, or a machine shared with younger family members?

Some applications may need environment restrictions, rather than
extensions, e.g. for security reasons.

Presumably people who use a gnome based linux will not have this problem
as things will be set up by the gnome login mechanism?

Using google to search for XDG_CURRENT_DESKTOP, reveals that a lot of
people have been having problems with this change.

I suspect better system designers would have redefined gnome-control-center
to alter the environment variable locally, and added a new command, e.g.
'new-control-center' which has to take advice from the XDG_CURRENT_SETUP
environment variable. Then gnome-control-center would set the environment
variable to preserve functionality and invoke new-control-center (or
whatever).

Aaron