Guix and $XDG_DATA_DIRS

[HiPhish <hiphish@posteo.de>]

Hello everyone,

I noticed that when I use Guix to install an application that has a desktop 
entry, such as Gimp, Inkscape or Krita, that application does not show up in 
my applications menu (using KDE on Kubuntu). After some digging I have found 
that the environment variable $XDG_DATA_DIRS is responsible for this.

From what I understand, Guix should set all the necessary environment 
variables by modifying the file $GUIX_PROFILE/etc/profile, which I then need to 
source in my .profile file. Here are its contents:

export PATH="${GUIX_PROFILE:-/gnu/store/83b17pr7rdyng48443iqn0f1z18dkpzk-
profile}/bin${PATH:+:}$PATH"
export GUILE_LOAD_PATH="${GUIX_PROFILE:-/gnu/store/
83b17pr7rdyng48443iqn0f1z18dkpzk-profile}/share/guile/site/2.2$
{GUILE_LOAD_PATH:+:}$GUILE_LOAD_PATH"
export GUILE_LOAD_COMPILED_PATH="${GUIX_PROFILE:-/gnu/store/
83b17pr7rdyng48443iqn0f1z18dkpzk-profile}/lib/guile/2.2/site-ccache$
{GUILE_LOAD_COMPILED_PATH:+:}$GUILE_LOAD_COMPILED_PATH"

As you can see, $XDG_DATA_DIRS is not being modified. I have added the 
following line to my .profile file:

    export XDG_DATA_DIRS="$GUIX_PROFILE/share/":$XDG_DATA_DIRS

Now all the applications do show up in my menu after a reboot. Is this an 
oversight or am I supposed to set that variable myself? And if it is the 
latter, where is the best place to set that variable so it picks it up when I 
install a new application without rebooting?