Completion error on OS X: GHCi lacks :complete support

[wfaler]

I just installed haskell-mode for Emacs on OS X, with the latest haskell-platform installed via homebrew, including the following packages (GHC 7.6.3):

• cabal (1.20.2)
• happy
• alex
• ghc-mod
• ghci-ng
• structured-haskell-mode
• stylish-haskell

When I try to code complete on a new cabal project, I get the following error, which is new to me (I have had completion working on OS X previously):
Error running timer ac-update-greedy': (error "GHCi lacks:complete' support")

..any pointers would be greatly appreciated..

[chrisdone]

You need GHC 7.8.

[chrisdone]

Oh, you're using ghci-ng? Try running: C-u M-! which ghci

[wfaler]

Thanks! Both comments where helpful and solve the problem in different ways. :)