anchor.diff:        export PATH
         echo $name loaded
       EOF
  -    exit 0
  +
  +    cat >> "$out/bin/load-''${name/env-/}-env" << EOF
  +    #!/bin/sh
  +
  +    source "$out/dev-envs/''${name/env-/}"
  +    EOF
  +    chmod +x "$out/bin/load-''${name/env-/}-env" 
     '';
   }
  
positive.code: 
    buildPhase = ''
      set -x
      mkdir -p "$out/dev-envs" "$out/nix-support"
      s="$out/nix-support/setup-new-modified"
      cp "$setupNew" "$s"
      # shut some warning up.., do not use set -e
  
negative.code:   # the buildNativeInputs environment variable.
    buildNativeInputs = [ ] ++ buildInputs ;
    name = "env-${name}";
    phases = [ "buildPhase" "fixupPhase" ];
    setupNew = substituteAll {
      src = ../../stdenv/generic/setup.sh;
      preHook="";
  