The problem is that I can't support every `coreutils` under existence. I already use `ps -U` in a bunch of places in different modules, and I like consistency. Prezto has had quite a bit of issues with Cygwin, and consequently, I'm thinking of removing any support for Cygwin.

I think that it will be better for a Cygwin user, perhaps you, to create a Cygwin specific fork of Prezto, and I can point people to it in the README.