`rgl` causing build failure on linux

My package builds on macOS but is failing on Linux. The linux build fails due to problems downloading a dependent package rgl. The error while downloading seems to be caused by gcc but I’m not sure exactly. You can find the build logs here. Is there something I should add to my .travis.yml to avoid this error.

https://travis-ci.org/avalcarcel9/rtapas/jobs/578919064#L8026:

configure: error: missing required header GL/glu.h

$ apt-file search GL/glu.h
<...>
libglu1-mesa-dev: /usr/include/GL/glu.h

Other Apt packages might be needed, too:

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