anchor.diff:  
   # Extra sources to include in the gopath
   , extraSrcs ? [ ]
  +
  +# Extra gopaths containing src subfolder
  +# with sources to include in the gopath
  +, extraSrcPaths ? [ ]
   
   # go2nix dependency file
   , goDeps ? null
  
positive.code: { go, govers, parallel, lib, fetchgit, fetchhg }:
  
  { name, buildInputs ? [], nativeBuildInputs ? [], passthru ? {}, preFixup ? ""
  
  
negative.code:     chmod -R u+w goPath/*
      mv goPath/* "go/src/${goPackagePath}"
      rmdir goPath
  
    '') + (lib.optionalString (extraSrcPaths != []) ''
      ${rsync}/bin/rsync -a ${lib.concatMapStrings (p: "${p}/src") extraSrcPaths} go
  
    '') + ''
      export GOPATH=$NIX_BUILD_TOP/go:$GOPATH
  