anchor.diff:    rustHostConfig = {
       x86_64-pc-mingw32 = "x86_64-pc-windows-gnu";
     }.${hostConfig} or hostConfig;
  +  rustTarget = if target == null then rustHostConfig else target;
   
     ccForBuild="${buildPackages.stdenv.cc}/bin/${buildPackages.stdenv.cc.targetPrefix}cc";
     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/${rustHostConfig}/${buildType}";
  +  releaseDir = "target/${rustTarget}/${buildType}";
   in
   
   stdenv.mkDerivation (args // {
  
positive.code:   verifyCargoDeps ? false
  , buildType ? "release"
  , meta ? {}
  
  , cargoVendorDir ? null
  , ... } @ args:
  
negative.code:       "CXX_${stdenv.hostPlatform.config}"="${cxxForHost}" \
        cargo build \
          ${stdenv.lib.optionalString (buildType == "release") "--release"} \
          --target ${rustTarget} \
          --frozen ${concatStringsSep " " cargoBuildFlags}
      )
  
  