Andreas Enge <andreas@enge.fr> writes:

> On Wed, Apr 29, 2015 at 11:52:30PM +0200, Taylan Ulrich Bayırlı/Kammer wrote:
>> Right.  I don't know what I did wrong before, but it actually seems to
>> work fine to put it in gl.scm.  New patch:
>
> Okay, looks good.

Actually, I hit the problem again now; it's during the compilation of
.scm files.

The problem seems to be that 'inherit' fields of packages are evaluated
eagerly, so when video.scm directly or indirectly imports gl.scm before
having bound the libva variable to its value, and the libva-without-mesa
definition in gl.scm tries to reference libva, it errors.

I can solve this by wrapping the libva-without-mesa definition in a
delay, and forcing it in the input field of mesa.  Is that OK?

New patch: