Same experience here--that .dir-locals.el was absolutely crucial. In case anyone is wondering how to turn on language pragmas with stack ghci in emacs, I did t

Same experience here--that .dir-locals.el was absolutely crucial. In case anyone is wondering how to turn on language pragmas with stack ghci in emacs, I did this for the project I'm working on, because I need OverloadedStrings turned on: ((haskell-mode . ((haskell-indent-spaces . 4) (hindent-style . "johan-tibell") (haskell-process-type . ghci) (haskell-process-path-ghci . "stack") (haskell-process-args-ghci . ("ghci" "--ghc-options" "-XOverloadedStrings")))))