Hello Dave, I can confirm that the same problem rises in Debian unstable with g++ version 5.2.1-17.
I don't know the solution. Having seen the reply of Alexey to original bug post in the mathgl mailing list https://groups.google.com/forum/?_escaped_fragment_=topic/mathgl/ioV2hTVfhq4#!topic/mathgl/ioV2hTVfhq4 I would try to rebuild and reupload mathgl without the c++11 support. What do you think? Regards Dimitris