Cabal Bug

Lemmih lemmih at gmail.com
Tue Apr 5 16:05:57 EDT 2005


On Apr 5, 2005 9:59 PM, Dominic Steinitz
<dominic.steinitz at blueyonder.co.uk> wrote:
> When I try to build using
> 
> ./Setup build
> 
> I get the following error:
> 
> Compiling Codec.Encryption.DESAux ( ./Codec/Encryption/DESAux.hs,
> dist/build/./Codec/Encryption/DESAux.o )
> 
> ./Codec/Encryption/DESAux.hs:19:0:
>     Illegal instance declaration for `Num [Bool]'
>         (The instance type must be of form (T a b c)
>          where T is not a synonym, and a,b,c are distinct type variables)
>     In the instance declaration for `Num [Bool]'
> 
> ./Codec/Encryption/DESAux.hs:21:0:
>     Illegal instance declaration for `Bits [Bool]'
>         (The instance type must be of form (T a b c)
>          where T is not a synonym, and a,b,c are distinct type variables)
>     In the instance declaration for `Bits [Bool]'
> 
>  So I added
> 
> Ghc-options:     -fglasgow-exts
> 
> to the cabal file. Now this module compiles but I still get the same error on
> a different module and I know -fglasgow-exts allows this to compile when I do
> it by hand.
> 
> ./Codec/ASN1/TLV.hs:140:0:
>     Illegal instance declaration for `Binary (State ([Octet], Offset))'
>         (The instance type must be of form (T a b c)
>          where T is not a synonym, and a,b,c are distinct type variables)
>     In the instance declaration for `Binary (State ([Octet], Offset))'
> 
> In fact, this seems to be the second time this module has been compiled and
> the first it completed successfully.
> 
> Compiling Codec.ASN1.TLV   ( ./Codec/ASN1/TLV.hs,
> dist/build/./Codec/ASN1/TLV.o )
> Compiling Codec.ASN1.X509  ( ./Codec/ASN1/X509.hs,
> dist/build/./Codec/ASN1/X509.o )
> 
> Why is cabal recompiling sources and why am I getting errors on the second
> compilation?

Pass '-v' to the Setup script to see how Cabal calls GHC.

-- 
Friendly,
  Lemmih


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