[Nix-dev] Haskell packages installation

[Dmitry Malikov]

On 07/16/2012 03:50 PM, Alexander Foremny wrote:
> Hello Dmitry,
>
> Nix uses the cabal build process (cabal configure, cabal build, cabal
> install) internally to install Haskell packages. However, this differs
> from just saying
>
>> $ cabal install split
> I suspect you are using incompatible GHC and split versions. As you
> can see Haskell packages in Nixpkgs are not only referenced by their
> name and version but also by the compiler's version they are built
> for. Thus, if you use GHC 7.4.2 you should install
> haskell-split-ghc7.4.2 for instance.
>
> Please check the version of GHC, for example by running.
>
>> $ ghc --version
> Another possible problem could be that you installed ghc instead of
> ghc-wrapper as ghc-wrapper takes care that GHC finds all the libraries
> installed by Nix.
>
> Regards,
> Alexander Foremny
>
> 2012/7/15 Dmitry Malikov <malikov.d.y at gmail.com>:
>> Hi.
>>
>> Could you please explain how haskell packages installation is really
>> works in Nixos?
>>
>> For example, there is split hackage package, which is named
>> haskell-split-ghc7.4.1-0.1.4.3.
>> I've installed it:
>> $ nix-env -q '*' | grep split
>> haskell-split-ghc7.4.1-0.1.4.3
>>
>> Then I'm trying to load it from ghci:
>>   > :m + Data.List.Split
>>
>> <no location info>:
>>       Could not find module `Data.List.Split'
>>       It is not a module in the current program, or in any known package.
>>
>> What am I doing wrong?
>>
>> It's hard to understand what happens after `nix-env -i
>> haskell-split-ghc7.4.1` (seems like it's not installed via cabal, just
>> «linked» to my profile).
>>
>> --
>> Best regards,
>> dmitry malikov
>> !
>>
>> _______________________________________________
>> nix-dev mailing list
>> nix-dev at lists.science.uu.nl
>> http://lists.science.uu.nl/mailman/listinfo/nix-dev

Hi, Alexander.

> Another possible problem could be that you installed ghc instead of 
> ghc-wrapper as ghc-wrapper takes care that GHC finds all the libraries 
> installed by Nix. 
You are right. Installing ghc-wrapper actually helps.

It's sad that fact that I need to use ghc-wrapper instead of ghc is 
really non obvious.

Thanks for help.


-- 
Best regards,
dmitry malikov
!