anchor.diff:      "--configure-option=--host=${hostPlatform.config}"
     ] ++ crossCabalFlags);
   
  -  useSeparateSetupDb = setupHaskellDepends != [] || isCross || isGhcjs;
  -
     setupCompileFlags = [
  -    (optionalString (!coreSetup) "-${nativePackageDbFlag}=${
  -      if useSeparateSetupDb
  -      then "$setupPackageConfDir"
  -      else "$packageConfDir"
  -    }")
  +    (optionalString (!coreSetup) "-${nativePackageDbFlag}=$setupPackageConfDir")
       (optionalString (isGhcjs || isHaLVM || versionOlder "7.8" ghc.version) "-j$NIX_BUILD_CORES")
       # https://github.com/haskell/cabal/issues/2398
       (optionalString (versionOlder "7.10" ghc.version && !isHaLVM) "-threaded")
  
positive.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
      ${nativeGhcCommand}-pkg --${nativePackageDbFlag}="$setupPackageConfDir" recache
    '')
  
      # For normal components
    + ''
      for p in "''${pkgsHostHost[@]}" "''${pkgsHostTarget[@]}"; do
        ${buildPkgDb ghc.name "$packageConfDir"}
  
negative.code:     echo "Build with ${ghc}."
      ${optionalString (hasActiveLibrary && hyperlinkSource) "export PATH=${hscolour}/bin:$PATH"}
  
      setupPackageConfDir="$TMPDIR/setup-package.conf.d"
      mkdir -p $setupPackageConfDir
      packageConfDir="$TMPDIR/package.conf.d"
      mkdir -p $packageConfDir
  
  