[Nix-dev] A Journey into the Haskell NG infrastructure: Part I

[Kirill Elagin]

>
> I cannot re-produce that, I'm afraid. On my system, both attributes
>
>   testHaskell1 = self.haskell-ng.packages.ghc784.ghcWithPackages (hp: []);
>   testHaskell2 = self.haskell-ng.packages.ghc784.ghcWithPackages (hp:
> with hp; [mtl]);
>
> seem to work fine.
>

Right, they do work fine, but _differently_, which seems strange.

I have:

~~~~
testHaskell1 = haskell-ng.packages.ghc784.ghcWithPackages (hp: []);
testHaskell2 = haskell-ng.packages.ghc784.ghcWithPackages (hp: [hp.mtl]);
~~~~

And here is what I get:

~~~~
› nix-shell '<nixpkgs>' -A testHaskell2 --dry-run

[nix-shell:~/proj/ghc/compiler/parser]$ exit

› nix-shell '<nixpkgs>' -A testHaskell1 --dry-run
these derivations will be built:
  /nix/store/s898z43nkjpzcizhcxcd71al9qd7plkh-ghc-7.8.4-src.tar.xz.drv
these paths will be fetched (73.48 MiB download, 862.92 MiB unpacked):
  /nix/store/w4il8kp2jhmhmaxplx7i04y838k583mk-ghc-7.4.2-binary

[nix-shell:~/proj/ghc/compiler/parser]$ exit
~~~~
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.science.uu.nl/pipermail/nix-dev/attachments/20150212/617a3650/attachment-0001.html