"Ambiguous module name `Control.Monad.CatchIO'" when compiling file about haskell-mode HOT 8 CLOSED

I should note that haskell-process-cabal-build does work, and the repl seems to have the correct module loaded.

from haskell-mode.

I don't think this is anything to do with haskell-mode.

Try:

$ ghci
> :l yourfile.hs

If it doesn't work please close this ticket.

from haskell-mode.

That doesn't work because my system has MonadCatchIO-transformers and MonadCatchIO-mtl. But my cabal file only selects one of these, so haskell-mode should be clever enough to do the same.

from haskell-mode.

So this is a feature request to run GHCi with Cabal dependency information and options.

I think cabal interactive will provide such a feature and cabal-ghci provides it in the mean time. Not sure it's worth bothering re-implementing such code in Emacs.

from haskell-mode.

Yes, the problem is that ghci does not care about your .cabal file and thus will not hide packages not listed in the .cabal file. One fix is to define a .ghci file that hides one of those packages.

from haskell-mode.

Well I've put a .ghci file in src, so it works fine from the command line if I launch ghci in there. However, the GHCI that is launched by haskell-emacs doesn't seem to respect that working directory. It seems it instead launches GHCI and then does a :cd. If I add ~/.ghci then it does work, but this doesn't quite seem like a solution. Thoughts?

from haskell-mode.

Try popping it in the same directory as your .cabal file, that's where it starts the process (and then indeed, it does :cd into the working directory). Should work?

from haskell-mode.

Aha - perfect, thank you! Apologies for somewhat wasting your time.

from haskell-mode.