anchor.diff:      echo "Build with ${ghc}."
       ${optionalString (hasActiveLibrary && hyperlinkSource) "export PATH=${hscolour}/bin:$PATH"}
   
  -  '' + (optionalString (setupHaskellDepends != []) ''
  +  '' + (optionalString useSeparateSetupDb ''
       setupPackageConfDir="$TMPDIR/setup-package.conf.d"
       mkdir -p $setupPackageConfDir
     '') + ''
  
positive.code:     "--configure-option=--host=${hostPlatform.config}"
    ] ++ crossCabalFlags);
  
    setupCompileFlags = [
      (optionalString (!coreSetup) "-${nativePackageDbFlag}=${
        if setupHaskellDepends != []
        then "$setupPackageConfDir"
        else "$packageConfDir"
      }")
  
negative.code:   # dependencies for the build machine.
    #
    # pkgs* arrays defined in stdenv/setup.hs
    + (optionalString useSeparateSetupDb ''
      for p in "''${pkgsBuildBuild[@]}" "''${pkgsBuildHost[@]}" "''${pkgsBuildTarget[@]}"; do
        ${buildPkgDb nativeGhc.name "$setupPackageConfDir"}
      done
  