bug#40872: First installed package on guix system is not instantly usable

[Stefan]

Hi!

I have a guix system and my user account has no package installed yet. After 
installing the first package – git-minimal in my case – this message is printed 
and I get this error when trying to use the new command:

building profile with 1 package...
Hinweis: Vielleicht möchten Sie die nötigen Umgebungsvariablen festlegen, indem 
Sie dies ausführen:

     GUIX_PROFILE="/home/stefan/.guix-profile"
     . "$GUIX_PROFILE/etc/profile"

Sie können sie auch mit `guix package --search-paths -p 
"/home/stefan/.guix-profile"' nachlesen.

stefan@guix ~$ git show
-bash: git: Kommando nicht gefunden.


The problem is that without a single package installed there is no user 
profile-link present:


stefan@guix ~$ echo $PATH
/run/setuid-programs:/home/stefan/.config/guix/current/bin:/run/current-system/profile/bin:/run/current-system/profile/sbin


This is of course easily solved by either following the hint or a logout and 
login:


stefan@guix ~$ exit
Abgemeldet
Connection to raspberry closed.
Computer:~ stefan$ ssh stefan@raspberry
Last login: Sun Apr 26 13:59:31 2020 
stefan@guix ~$ echo $PATH
/run/setuid-programs:/home/stefan/.config/guix/current/bin:/home/stefan/.guix-profile/bin:/run/current-system/profile/bin:/run/current-system/profile/sbin


However, this gives a bad first impression to users. Moreover users may think 
that a logout/login cycle or manually following the hint could be necessary 
after each package installation. They may get annoyed by this.


Bye

Stefan