Hello Guix,

There was several discussions about adding file-system utils packages to
the system profile based on the types in the “file-systems” field.

I tried implementing this in the attached patch but I'm currently stuck 
and
need some help. I've probably overlooked something basic but I can;t put 
a
finger on it... Guix compile successfully with the patch and testing
“file-system-utils” in “guix repl” returns a list of packages as 
expected.
But when I try building a system/vm the packages aren't added to the
system's profile as I expected. From what I understand, that function as
used in “file-system-service-type” should get as arguments the list of
file-systems defined in the operating-system and should return a list of
packages, themselves appended to the system's profile list of packages.

Halp! What am I missing?

I also welcome any suggestion UI wise, currently the only change is the
additions of the “utils?” filed in the “file-system” record.

- Brice