anchor.diff:  }:
   
   stdenv.mkDerivation rec {
  -  name = "nix-1.2pre2793_d950cfe";
  +  name = "nix-1.2pre2910_b674665";
   
     src = fetchurl {
  -    url = "http://hydra.nixos.org/build/2955697/download/4/${name}.tar.bz2";
  -    sha256 = "f91367d8e7ed795b2bc9a47fb3ecff00d005633f248ecaafa25e8e101a5dc682";
  +    url = "http://hydra.nixos.org/build/3031673/download/4/${name}.tar.bz2";
  +    sha256 = "fa9849f69a262547856190fe1a24e6d6bd15344fe2ef0a0e54c35ab172074a22";
     };
   
     buildNativeInputs = [ perl pkgconfig ];
  
positive.code:     configureFlags =
        ''
          --with-store-dir=${storeDir} --localstatedir=${stateDir}
          --with-dbi=${perlPackages.DBI}/lib/perl5/site_perl
          --with-dbd-sqlite=${perlPackages.DBDSQLite}/lib/perl5/site_perl
          --disable-init-state
          --enable-gc
          CFLAGS=-O3 CXXFLAGS=-O3
        '' + stdenv.lib.optionalString (
            stdenv.cross ? nix && stdenv.cross.nix ? system
        ) ''--with-system=${stdenv.cross.nix.system}'';
        
      doInstallCheck = false;
    };
  
  
negative.code:   configureFlags =
      ''
        --with-store-dir=${storeDir} --localstatedir=${stateDir}
        --with-dbi=${perlPackages.DBI}/${perl.libPrefix}
        --with-dbd-sqlite=${perlPackages.DBDSQLite}/${perl.libPrefix}
        --with-www-curl=${perlPackages.WWWCurl}/${perl.libPrefix}
        --disable-init-state
        --enable-gc
        CFLAGS=-O3 CXXFLAGS=-O3
  