Open
Description
I remember that back when I was starting to use Haskell, back in the days of GHC version 6 and when cabal-install was all we had, I was frustrated that I couldn't pass things like -ddump-splices directly to configure or build. At the time it was confusing to me that the GHC manual would say "pass this flag", but you needed to know how to plumb that flag through to GHC.
It would be really cool to detect that the user has attempted to pass a GHC flag, and tell them about how ghc-options work with stack. This might work by catching the optparse-applicative error and turning it into a different variety of error if it matches a GHC flag name.