[Haskell-cafe] Problem building HXQ on Mac OS 10.5.5

Judah Jacobson judah.jacobson at gmail.com
Wed Dec 3 12:43:18 EST 2008

On Tue, Dec 2, 2008 at 9:49 AM, Tobias Kräntzer
<info at tobias-kraentzer.de> wrote:
> Hi,
> I'm new to haskell and wonted to start tinkering a bit with this language,
> specifically with HXQ. I have installed ghc with macports.
> Now while building HXQ I get the following error:
> Main.hs:20:9:
>    Not in scope: type constructor or class `C.SomeException'
> Unfortunately I'm also new to Mac OS X. Before I developed on Linux.
> It would be great, if someone could give me a hint.

I think you should be able to build it if you manually download the
.tar.gz file from Hackage and then type:

runghc Setup configure
runghc Setup build
runghc Setup install

The Control.Exception module was changed in ghc-6.10.1 (specifically,
in the base-4 package).  HXQ's code assumes that when compiling with
ghc-6.10 you're always using base-4; however, that compiler also comes
with base-3.0.3 which is a compatibility package providing the same
interface as previous versions of ghc.  The 'cabal install' program
tries to be helpful and selects base-3.0.3 (since HXQ does not specify
which to use), causing the above error.

I've cc'd the package author on this.  A possible fix would be to use
the extensible-exceptions package, or otherwise just copy the logic
from its .cabal file.


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