Thanks for the review! I've pushed the patch.

On Wed, 27 Dec 2017 23:12:30 +0100
Marius Bakke <mbakke@fastmail.com> wrote:

> Rutger Helling <rhelling@mykolab.com> writes:
> 
> > I've made one more change. In the Mesa 17.3.x series S3TC
> > compression is now built-in (the patent expired). This means the
> > s2tc input is now unnecessary, so I've removed it.
> >
> > I confirmed with guix gc --references $(guix build mesa) that there
> > wasn't a reference to s2tc anymore that was in 17.2.x.  
> 
> Thanks for the attention to detail here.  The patch LGTM!