tcnksm/dockerfile-centos-perl — pull request #1 by DQNEO (2014-12-11 12:19:26+00:00)
Title: disable threads

Use of threads is not recommended among perl mongers.

http://blog.64p.org/entry/20090629/1246239835

For your info, the official repository provides non thread version of Dockerfile.
I think you should have copied this.
https://github.com/Perl/docker-perl/blob/master/5.020.001-64bit/Dockerfile