Hi Marius!

> This only works when you already have 'gstreamer' in the profile, right?

`gstreamer' is propagated by the gst plugins.

> I don't think the first example can ever work short of wrapping the
> executable?

WebKitGTK-based browsers look for the plugins in the GST_PLUGIN_PATH
and the GST_PLUGIN_SYSTEM_PATH environment variables.



I retested today: actually I realized that it works if I clear
~/.cache/gstreamer-1.0 :p

The problem is that the cache goes stale when the path to the plugins
changes.
It's a rather general problem with Guix, I think it's been discussed
before.

If we had a way to test for the cache staleness, we could add some code
to the Epiphany wrapper that clears the cache if stale.

-- 
Pierre Neidhardt
https://ambrevar.xyz/