Automake 1.15 fails its tests in ‘core-updates’ due to incompatibilities
with Perl 5.22.1.

Previously we were using Perl 5.16.1, which worked fine.

See <http://hydra.gnu.org/build/945654/nixlog/2/raw> for a build log.
Attached is the full ‘test-suite.log’.

Ludo’.