[Debian-science-sagemath] apt upgrading issue:

[François Bissey]

> On 11/08/2016, at 22:51, Jerome BENOIT <calculus at rezozer.net> wrote:
> 
> Second, I am surprised to meet PNG here.

Surprising but the dependency is correct. m4ri which is a dependency
of brial should have a matching dependency on PNG as well.

PNG is an automatic dependency of brial, if PNG is not found it
then looks for libgd instead. But the configure logic doesn’t bail
if both are missing so it should be possible to produce a PNGless
libgd_less brial.

François