How to use REPL with stack?

[mrkkrp]

So I finally fully switched to stack. Now when I press C-c C-l and specify target, say tests, I get the following (after “Haskell process died” message):

The following target packages were not found: tests

What additional configuration/magic do I need to use to make REPL work with stack?

[mrkkrp]

Fine, stack ghci uses different naming scheme for components of package. This explains the error message. Can you tell how haskell-mode decides what to use cabal repl or stack ghci and which arguments are passed to stack ghci, how they are generated?

Sorry, I'm usually having hard time reading source of some parts of haskell-mode.

[PierreR]

This is what I use in my .spacemacs:

  (setq 
        ghc-ghc-options '("-fno-warn-missing-signatures")
        haskell-compile-cabal-build-command "cd %s && stack build"
        haskell-process-type 'stack-ghci
        haskell-interactive-popup-errors nil
        haskell-process-args-stack-ghci '("--ghc-options=-ferror-spans" "--with-ghc=ghci-ng")
        haskell-process-path-ghci "stack"
)

Of course you don't need the ghci-ng bit.

[mrkkrp]

@PierreR, Thank you for sharing the config. haskell-process-type did the trick for me.

Tip for the maintainers: add a note about haskell-process-type to readme file along with other things that may need adjusting to work with Stack, this will definitely save time for some people.

Typing myproject:test:tests is still a bit long. Am I the only one who uses REPL with targets different from default? Previously haskell-mode had questions on loading by default, now I need to enable them manually, but anyway there are too many questions and no help (IDO or something would be great) to choose target. All this is disappointing.

I tried to read source code of haskell-mode to be in position to fix this stuff, but it feels like spaghetti or result of long-long accumulation of small changes without thinking about overall readability and design, so I gave up. No complaints, I appreciate that people maintain haskell-mode at all, just saying.

Closing this.