[Nix-dev] Discussion: env vars as glue

[Lluís Batlle i Rossell]

On Mon, Apr 15, 2013 at 10:17:23PM +0300, phreedom at yandex.ru wrote:
> On Понедельник 15 апреля 2013 18:59:52 Lluís Batlle i Rossell wrote:
> > What uses do you have for:
> > ALSA_PLUGIN_DIRS
> 
> This is used for LADSPA plugins(various sound processing apps) and for 
> input/output plugins(eg by pulseaudio).

Ok, now, can we make this a nixos-only option? Containing only a path prepared
by nixos. People who want LADSPAT plugins, set them up with nixos.

Pulseaudio is referred by full store path, iirc, not using this variable
(/etc/asound.conf)

> > GST_PLUGIN_PATH
> 
> Gstreamer plugins which do all the work. Apparently these are loaded 
> dynamically. Typical case: kde app plays media via phonon, which uses 
> phonon_backend_gstreamer to do the actual processing.

Don't people usually set this up in nixos, instead of the user profiles? What
kind of plugins people install with nix-env?

> > MOZ_PLUGIN_PATH
> no idea.

Firefox plugins. But the wrapper does a better job than this, as I stated
before.

> > QTWEBKIT_PLUGIN_PATH
> Apparently, this helps webkit steal mozilla's extensions.  Likely any kde app 
> which is a browser or can use KParts(such as akregator) would want this set.

Maybe this can be set easily up to work with a wrapper like firefox? What kind
of browsers would use that? If only konqueror, maybe that can be handled by
nixos instead.

> > QT_PLUGIN_PATH
> 
> I'm not at all sure, but the dirs it links to aren't empty and they link to 
> things like phonon...
> 
> > STRIGI_PLUGIN_PATH
> The idea was that every kde app would ship with analyzers for their specific 
> data formats and possibly common specialized data formats to enable proper 
> metadata extraction. Plugins can be direcly loaded by an app linking to 
> libstreamanalyzer or by a nepomuk service. While strigi seems to be on its way 
> out of kde 4.11, it's only because there's another replacement plugin 
> framework coming.

Can this be set up by nixos only, and not using the user profiles?

> You managed to overlook the innocently-looking KDEDIRS. On a typical KDE 
> install this place contains 1k+ libs. Among these are KIPI plugins shared by 
> at least gwenview, krita and digikam, Kparts plugins which are at least shared 
> by konqueror and akregator and are always installed by the app supplying the 
> part.... While KDE usually requires ABI compatibility in such cases, it 
> doesn't help client apps  compiled against newer version.

Right, KDEDIRS! :)

Don't most KDE programs require being set up by nixos anyway? Or this KDEDIRS
was an addition towards allowing the install of extra KDE programs in profiles?
This does not help much installing KDE programs without KDE in NixOS, in any case.

Regards,
Lluís.