Revert "Try @wds15 suggestion to not install libc"
Revert "Try @wds15 suggestion to not install libc"

This reverts commit 1233019400b86565237f4a7dab4fec5fc2f48884.

stan-dev/math,stan-dev/math,stan-dev/math,stan-dev/math,stan-dev/math,stan-dev/math,stan-dev/math,stan-dev/math,stan-dev/math