I was investigating how to build for production (I'm on a Mac, I want to build for Linux), and noticed that there's a flag:

stack - The Haskell Tool Stack

Available options:
  --os OS                  Operating system, e.g. linux, windows

I cannot find any documentation on this. If it's available I'd appreciate a nudge in the right direction, but otherwise, some documentation for the flag would be appreciated.

I understood the flag as being the target OS for builds, but when passing "--os linux" in a build on a Mac, I get a Mach-O binary, not a linux compatible binary.