anchor.diff:      runHook preInstall
   
       mkdir -p $out
  +    mkdir "$NIX_BUILD_TOP/${name}"
       pushd "$NIX_BUILD_TOP/go"
       if [ -n "$subPackages" ]; then
         subPackageExpr='/\('
  
positive.code:     rmdir extraSrc
  
    '') + ''
      export GOPATH=$NIX_BUILD_TOP/go:$GOPATH
  
      runHook postConfigure
    '';
  
negative.code:     fi
      while read f; do
        echo "$f" | grep -q '^./\(src\|pkg/[^/]*\)/${goPackagePath}'"$subPackageExpr" || continue
        mkdir -p "$(dirname "$NIX_BUILD_TOP/${name}/$f")"
        cp "$NIX_BUILD_TOP/go/$f" "$NIX_BUILD_TOP/${name}/$f"
      done < <(find . -type f)
      popd
  
      pushd "$NIX_BUILD_TOP"
      mkdir -p "$out/share/go"
      tar --sort=name --owner=0 --group=0 --numeric-owner \
        --mode=go=rX,u+rw,a-s \
        --mtime=@946713600 \
        -c "${name}" | brotli --quality 6 --output "$out/share/go/files.tar.br"
      popd
  
      mkdir -p $bin
  