On Mon, Oct 24, 2011 at 2:13 PM, Yves Parès <
limestrael@gmail.com> wrote:
> I'm using GHC 7.2.1 and cabal-install 0.8 (Cabal 1.8.0.2), and when
> "cabal install rsa"
>
> I got the error
> $ cabal install rsa
> Resolving dependencies...
> Configuring RSA-1.0.6.2...
> Preprocessing library RSA-1.0.6.2...
> Preprocessing executables for RSA-1.0.6.2...
> Building RSA-1.0.6.2...
> [1 of 1] Compiling Codec.Crypto.RSA ( Codec/Crypto/RSA.hs,
> dist/build/Codec/Crypto/RSA.o )
>
> Codec/Crypto/RSA.hs:580:10:
> Duplicate instance declarations:
> instance Random Word8 -- Defined at Codec/Crypto/RSA.hs:580:10-21
> instance Random Word8 -- Defined in System.Random
> cabal: Error: some packages failed to install:
> RSA-1.0.6.2 failed during the building phase. The exception was:
> ExitFailure 1
>
> Apparently it's an instance being declared twice.
> However RSA hackage page states that it compiles under GHC 7.2:
>
http://hackage.haskell.org/package/RSA
>