(In reply to Dominique Leuenberger from comment #0)
> gupnp-tools 0.8.12 uses @PKGDATADIR@ inside the .desktop.in.in file, but
> those files are not handled by configure as config files and there is o
> logic to replace @PKGDATADIR@ in those files.
> 
> Besides that: The icons should not be installed to obscure directories, as
> tools like appstream-builder and flatpak builder will not extract icons from
> /usr/share/icons in order to produce meta-data - further to that, the icon
> should be listed without extension

Either the icon is in the proper icon dir and then it takes the icon name as you suggest or it takes the full path :)

> (and I doubt there is need to 'translate'> the icon entry in the .desktop file)

A translator comment for this was added recently

@PKGDATADIR@ think Fixed on master with c63983ea50b8c224787e9dc1e670d2e2104fbf7d.

(In reply to Jens Georg from comment #1)
> (In reply to Dominique Leuenberger from comment #0)
> >
> > (and I doubt there is need to 'translate'> the icon entry in the .desktop file)
> 
> A translator comment for this was added recently
> 
> @PKGDATADIR@ think Fixed on master with

Did you mean to write "I think @PKGDATADIR@ was fixed in master with"?

> > @PKGDATADIR@ think Fixed on master with
> 
> Did you mean to write "I think @PKGDATADIR@ was fixed in master with"?

Er. Yes :)

(In reply to Jens Georg from comment #3)
> > > @PKGDATADIR@ think Fixed on master with
> > 
> > Did you mean to write "I think @PKGDATADIR@ was fixed in master with"?
> 
> Er. Yes :)

Good. :) Would feel really good if you update the comment for me.

I've cherry-picked the mentioned commit and can confirm it fixes the problem.