anchor.diff:    cxxForBuild="${buildPackages.stdenv.cc}/bin/${buildPackages.stdenv.cc.targetPrefix}c++";
     ccForHost="${stdenv.cc}/bin/${stdenv.cc.targetPrefix}cc";
     cxxForHost="${stdenv.cc}/bin/${stdenv.cc.targetPrefix}c++";
  -  releaseDir = "target/${stdenv.hostPlatform.config}/release";
  +  releaseDir = "target/${stdenv.hostPlatform.config}/${buildType}";
   
   in stdenv.mkDerivation (args // {
     inherit cargoDeps;
  
positive.code:     # rename the output dir to a architecture independent one
      mapfile -t targets < <(find "$NIX_BUILD_TOP" -type d | grep '${releaseDir}$')
      for target in "''${targets[@]}"; do
        rm -rf "$target/../../release"
        ln -srf "$target" "$target/../../"
      done
  
  
negative.code:       "CC_${stdenv.hostPlatform.config}"="${ccForHost}" \
        "CXX_${stdenv.hostPlatform.config}"="${cxxForHost}" \
        cargo build \
          --${buildType} \
          --target ${stdenv.hostPlatform.config} \
          --frozen ${concatStringsSep " " cargoBuildFlags}
      )
  