bug#35594: bug#36376: Application menu of desktop environment not automatically updated

[Maxim Cournoyer]

Hello Ludovic and Leo,

Leo Prikler <leo.prikler@student.tugraz.at> writes:

> Hi Ludo,
>
> Am Dienstag, den 03.11.2020, 23:46 +0100 schrieb Ludovic Courtès:
>> Ludovic Courtès <ludo@gnu.org> skribis:
>> 
>> > This is not news to us, but as
>> > <https://distrowatch.com/weekly.php?issue=20190624#guixsd> notes,
>> > the
>> > application menu of desktop environments is not automatically
>> > updated
>> > when a package is installed or removed.  It’d be great if we could
>> > somehow notify the desktop environment.
>> 
>> We’ve investigated today on IRC with Maxim and Leo P. and here’s the
>> summary of our findings:
> Seeing my name thrown around more and more lately makes me blush a
> little.
>> [...]
>> 
>> The GLib patch below is an attempt to monitor ~/.guix-profile and to
>> treat changes to that symlink as if they were changes to
>> ~/.guix-profile/share/applications (which contains ‘.desktop’ files.)
>> It actually builds but I haven’t tested it yet.  :-)
>> 
>> WDYT?

Pretty cool!  It'd keep on working even if we even clean up /etc/profile
from the hardcoded defauts environment variables (say, if we merge one
of the proposed solution of https://issues.guix.gnu.org/22138).

> Not having tested it either, I think that we should also listen on
> /run/current-system/ (if it exists), so that changes to the system as
> done by `reconfigure` are picked up.  This includes most importantly
> changes to the GNOME ecosystem itself.

I agree that it seems useful and important to add a monitor on the
/run/current-system as well.

Thank you!

Maxim