Bug#758888: lmms: Provide links to LADSPA plugins in /usr/lib/ladspa

[Petter Reinholdtsen]

[Antonio Ospite]
> Dear Maintainer,
> 
> lmms provides quite a few LADSPA plugins, what about making them
> available to other programs too?

Thank you for the idea.  I've been wondering about this a bit lately,
and one idea was to change the lmms build to install the LADSPA
plugins in /usr/lib/ladspa/.  It seemed like a good idea until I was
told that the plugins included in lmms also are included in other
packages, and might cause conflicts.  I also realised that the
/usr/lib/ladspa/ content is architecture dependent, and adding a file
there break multi-arch support.  It is thus unclear to me how to
handle this in a good way.

For example, if someone install the amd64 and i386 packages including
LADSPA plugins, which ones should show up in /usr/lib/ladspa/?  They
will work for some programs and not others.  One could try to store
them in /usr/lib/<arch-triplet>/ladspa/ instead, but programs
supporting the LADSPA specification will not find them there as the
specification do not mention those directories.  Perhaps the best way
is to use a /etc/profile.d/ fragment to set the LADSPA_PATH
environment variable to wherever the plugins are installed, and drop
the idea of one canonical place to find them all?  Freshly installed
plugin packages will only take effect after login / starting a new
shell, but at least it will handle many plugins in an multi-arch
environments.  Or perhaps all programs should be started using a
wrapper sourcing LADSPA paths from a .d directory during startup?

I welcome feedback and ideas on how to properly handle this, in a way
that work with all or most programs using LADSPA plugins,

-- 
Happy hacking
Petter Reinholdtsen