Currently, stack script only allows specifying arguments to the user's program, not to the ghc invocation. Should probably use --ghc-arg as described in https://downloads.haskell.org/~ghc/master/users-guide/runghc.html , rather than passing the arguments directly. I suggest adding the following:

• --ghc-options, which works just like the argument to build
• --ghc-arg, which allows passing it to just the script command's ghc invocation.