Ubuntu Segfaults on Exit

[retroandchill]

Currently, the build for Ubuntu generates a segmentation fault error when Ruby shuts down. This is not desired as it causes Ruby to return a non-zero exit code, which offuscates the actual success state of the program. Figure out why this is and resolve the issue.

I already posted on /r/cpp_questions, so feel free to look through any of the suggestions offered there.
https://www.reddit.com/r/cpp_questions/comments/17yicec/segmentation_fault_from_sdl_on_thread_terminate/