anchor.diff:    cargoBuildFlags = [ "--features no-self-update" ];
   
     patches = lib.optionals stdenv.isLinux [
  -    (let
  -      libPath = lib.makeLibraryPath [
  -        zlib # libz.so.1
  -      ];
  -    in
  -      (runCommand "0001-dynamically-patchelf-binaries.patch" { CC=stdenv.cc; patchelf = patchelf; libPath = "$ORIGIN/../lib:${libPath}"; } ''
  -       export dynamicLinker=$(cat $CC/nix-support/dynamic-linker)
  -       substitute ${./0001-dynamically-patchelf-binaries.patch} $out \
  -         --subst-var patchelf \
  -         --subst-var dynamicLinker \
  -         --subst-var libPath
  +    (runCommand "0001-dynamically-patchelf-binaries.patch" { CC=stdenv.cc; patchelf = patchelf; libPath = "$ORIGIN/../lib:${libPath}"; } ''
  +     export dynamicLinker=$(cat $CC/nix-support/dynamic-linker)
  +     substitute ${./0001-dynamically-patchelf-binaries.patch} $out \
  +       --subst-var patchelf \
  +       --subst-var dynamicLinker \
  +       --subst-var libPath
       '')
  -    )
     ];
   
     doCheck = !stdenv.isAarch64 && !stdenv.isDarwin;
  
positive.code:       ln -s rustup $link
      done
      popd
  
      # tries to create .rustup
      export HOME=$(mktemp -d)
  
negative.code: 
    cargoSha256 = "0ghjrx7y25s6rjp06h0iyv4195x7daj57bqza01i1j4hm5nkhqhi";
  
    nativeBuildInputs = [ makeWrapper pkgconfig ];
  
    buildInputs = [
      curl zlib
  