anchor.diff:  
       configurePhase = ''
         runHook preConfigure
  -      cp ${bootstrapCompiler}/bin/nim bin/
         echo 'define:nixbuild' >> config/nim.cfg
         runHook postConfigure
       '';
  
positive.code:       ln -sf $out/nim/bin/nim $out/bin/nim
        ln -sf $out/nim/lib $out/lib
        ./install.sh $out
        runHook postInstall
      '';
  
  
negative.code:     buildPhase = ''
        runHook preBuild
        local HOME=$TMPDIR
        make -j$NIX_BUILD_CORES
        ./bin/nim c --parallelBuild:$NIX_BUILD_CORES koch
        ./koch boot $kochArgs --parallelBuild:$NIX_BUILD_CORES
        ./koch toolsNoExternal $kochArgs --parallelBuild:$NIX_BUILD_CORES
        ./bin/nim js -d:release tools/dochack/dochack.nim
        runHook postBuild
      '';
  
  