You can build GHC with musl libc and then make truly portable static binaries but it isn't that easy.
https://www.reddit.com/r/haskell/comments/37m7q7/ghc_musl_ea...
https://github.com/mitchty/alpine-linux-ghc-bootstrap
Recently updated last week to 8.0.1, and its submitted upstream but not yet accepted because alpine linux 3.4 is about to come out.
If you want to try it now you can docker pull mitchty/alpine-ghc:8.0
I haven't tried building a statically linked musl ghc, and I honestly don't know how, but it'd be great to figure out. Any pointers? Speaking of static musl builds, that can be a good choice to create a single bindist of GHC that works on CentOS, Debian, Alpine, and any other Linux distro. Seeing how Docker defaults to Alpine images, it could be beneficial in that regard as well.