anchor.diff:      if [ -z "$allowVendoredSources" ]; then
         find go/src/$goPackagePath -type d \( -name vendor -or -name Godeps \) -prune -exec rm -r {} \;
       fi
  -  '' + flip concatMapStrings extraSrcs ({ src, goPackagePath }: ''
  +  '' + flip concatMapStrings extraSrcs ({ src, goPackagePath, ... }: ''
       mkdir extraSrc
       (cd extraSrc; unpackFile "${src}")
       mkdir -p "go/src/$(dirname "${goPackagePath}")"
  
positive.code: 
    disallowedReferences = optional (!allowGoReference) go;
  
    passthru = passthru // optionalAttrs (goPackageAliases != []) { inherit goPackageAliases; };
  
    # I prefer to call this dev but propagatedBuildInputs expects $out to exist
    outputs = [ "out" "bin" ];
  
negative.code: # IE: programs coupled with the compiler
  , allowGoReference ? false
  
  , meta ? {}, ... } @ args:
  
  if disabled
    then throw "${name} not supported for go ${go.meta.branch}"
  