[bug#53676] [PATCH 3/5] gnu: pulseaudio: Graft to adjust configuration.

[Liliana Marie Prikler <liliana.prikler@gmail.com>]

Am Dienstag, dem 01.02.2022 um 15:20 -0500 schrieb Maxim Cournoyer:
> Hi Liliana,
> 
> Liliana Marie Prikler <liliana.prikler@gmail.com> writes:
> 
> > Am Montag, dem 31.01.2022 um 23:19 -0500 schrieb Maxim Cournoyer:
> > > * gnu/packages/pulseaudio.scm (pulseaudio/fixed): New variable.
> > > (pulseaudio)[replacement]: Graft package with it.
> > > ---
> > >  gnu/packages/pulseaudio.scm | 18 ++++++++++++++++++
> > >  1 file changed, 18 insertions(+)
> > > 
> > > diff --git a/gnu/packages/pulseaudio.scm
> > > b/gnu/packages/pulseaudio.scm
> > > index fe028b5202..f529717ee1 100644
> > > --- a/gnu/packages/pulseaudio.scm
> > > +++ b/gnu/packages/pulseaudio.scm
> > > @@ -178,6 +178,7 @@ (define-public libsamplerate
> > >  (define-public pulseaudio
> > >    (package
> > >      (name "pulseaudio")
> > > +    (replacement pulseaudio/fixed)
> > >      (version "15.0")
> > >      (source (origin
> > >               (method url-fetch)
> > > @@ -269,6 +270,23 @@ (define-public pulseaudio
> > >      ;; 'LICENSE' for details.
> > >      (license l:gpl2+)))
> > >  
> > > +(define pulseaudio/fixed
> > > +  (package
> > > +    (inherit pulseaudio)
> > > +    (arguments
> > > +     (substitute-keyword-arguments (package-arguments
> > > pulseaudio)
> > > +       ((#:phases phases)
> > > +        `(modify-phases ,phases
> > > +           (add-after 'unpack 'customize-default-script
> > > +             (lambda _
> > > +               (call-with-port
> > > +                (open-file "src/daemon/default.pa.in" "a")
> > > +                (lambda (port)
> > > +                  (format port "~%\
> > > +### Include extra script files configured via the pulseaudio-
> > > service-type.
> > > +.nofail
> > > +.include /etc/pulse/default.pa.d~%")))))))))))
> > > +
> > Note that there should be a .fail afterwards.  
> 
> Hmm.  I simply duplicated the existing two lines used by PulseAudio
> itself.  I believe they do not care because it appears completely at
> the end of the file.
I think we would need to care though, because one could write a gexp
that appends to default.pa, but then has unclear semantics.

> > As Leo pointed out, we shouldn't do too many "feature grafts", so
> > instead it might be worth moving this part to pulseaudio-service-
> > type in some way, no?
> 
> I'd prefer to keep it like this, for simplicity; we need to rebuild
> the world soon anyway to fix a Rust CVE, so we can batch things
> easily.
Can you define "simplicity" here?  In my opinion, services/stuff.scm or
/etc/config.scm provide an easier point of change/extension than
packages do -- particularly also because pulseaudio-service-type (even
with this patch set) does not allow changing the pulseaudio package.

For the record, if you're wondering why pulseaudio-service-type doesn't
have a configuration knob for adding the pulseaudio package: pulseaudio
is currently managed per user session through dbus, not shepherd.  It'd
be nice to have systemd-levels of control over user services, but we're
not there yet.

Cheers