Re: [PATCH] gnu: Add gxtuner.

[Ricardo Wurmus <rekado@elephly.net>]

Kei Kebreau <kei@openmailbox.org> writes:

> This package is reproducible and clears the linting process on my
> end. Sadly I'm not skilled enough with JACK to check the functionality
> of the package. :-/

Using JACK on GuixSD effectively requires a little additional effort.  I
have this in my system configuration to be able to use JACK’s realtime
mode:

  (users (list (user-account
                (name "rekado")
                (comment "rekado")
                (group "rekado")
                (supplementary-groups '(… "realtime"))
                (home-directory "/home/rekado"))))
  (groups (cons* (user-group (name "rekado") (id 1000))
                 (user-group (name "realtime"))
                 %base-groups))
  …
  (services (cons* (pam-limits-service
                    (list
                     (pam-limits-entry "@realtime" 'both 'rtprio 99)
                     (pam-limits-entry "@realtime" 'both 'memlock 'unlimited)))
                   …))

This means: add my user account to a new group “realtime” and then
raise the realtime priority for this group.  Also drop memory
restrictions for members of this group.

Then you close all applications that might currently be using the audio
interface directly.  Make sure pulseaudio is not running.  Then run the
JACK daemon with the ALSA backend:

    jackd -d alsa

At this point you can start any application that needs JACK.  To connect
wires between JACK applications and the audio interface ports I
recommend using “patchage”, a graphical patcher that shows you all audio
ports on all JACK appplications and lets you draw connections between
them.

Hope this helps!

~~ Ricardo