[Haskell-cafe] GHC 6.12 on OS X 10.5
aslatter at gmail.com
Mon Dec 21 17:05:20 EST 2009
On Mon, Dec 21, 2009 at 3:43 PM, Tom Tobin <korpios at korpios.com> wrote:
> This time the install died on HJScript:
> [ 2 of 26] Compiling HJScript.Monad ( src/HJScript/Monad.hs,
> dist/build/HJScript/Monad.o )
> A pattern match on a GADT requires -XGADTs
> In the pattern: EmptyBlock
> In the definition of `mappend': mappend EmptyBlock b = b
> In the instance declaration for `Monoid (Block ())'
> cabal: Error: some packages failed to install:
> HJScript-0.4.5 failed during the building phase. The exception was:
> ExitFailure 1
> I have no idea what to do next, so I'll probably bring this particular
> issue up on the Happstack list next.
This one I can help with. You need to modify the .cabal file for
HJScript slightly. To do this:
cabal unpack HJScript
And then add 'GADTs' to the 'Extensions:' list.
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