Hi, 

I have a Mac OS X workstation and want to compile a cli for Linux (and potentially Windows) in addition to OS X. 

I could not find anything but https://ghc.haskell.org/trac/ghc/wiki/CrossCompilation. 
This has an explanation how I can build a cross compiling GHC for a specific combination of build and target system/architecture. 
Stack has an open issue regarding cross compilation.

Is that really all there is out there? 

Regards 
Jan