Re: [Haskelldb-users] ghc 6.6.1 compilation

[Bjorn B. <bri...@cs...>]

On Sep 9, 2007, at 2:00 , Peter Simons wrote:

> Hi,
>
> I tried to build the current CVS head with GHC 6.6.1. To make
> Cabal work, I had to change the extensions field as follows:
>
> --- a/haskelldb.cabal
> +++ b/haskelldb.cabal
> @@ -7,7 +7,7 @@ License: BSD3
>  build-depends: haskell98, base
>  Extensions: ExistentialQuantification,
>              OverlappingInstances,
> -            AllowUndecidableInstances,
> +            UndecidableInstances,
>              MultiParamTypeClasses
>  Synopsis: SQL unwrapper for Haskell.
>
> During the build, however, I get this error:
>
> src/Database/HaskellDB/Database.hs:116:16:
>     The scoped type variables `ef' and `f'
>       are bound to the same type (variable)
>       Distinct scoped type variables must be distinct
>     In the pattern: _ :: Rel (RecCons ef (Expr ea) er)
>     In the definition of `getRec':
> 	getRec vfs (_ :: Rel (RecCons ef (Expr ea) er)) (f : fs) stmt
> 		 =3D do x <- getValue vfs stmt f
> 		      r <- getRec vfs (undefined :: Rel er) fs stmt
> 		      return ((RecCons x) . r)
>     In the definition for method `getRec'
>
> I'm not sure how to fix that. Can anyone help me, please?

You said "CVS head", if that's correct, use the darcs repo instead:

darcs get http://darcs.haskell.org/haskelldb/

The currect darcs version builds with GHC 6.6, I haven't tested 6.6.1 =20=

myself.

/Bj=F6rn