Fix for thread safety issue with ERB

erb_fix.rb

# Monkey patch to make ERB stop using the global TOPLEVEL_BINDING
ERB.class_eval do
  def result(b=binding)
    if @safe_level
      proc {
        $SAFE = @safe_level
        eval(@src, b, (@filename || '(erb)'), 0)
      }.call
    else
      eval(@src, b, (@filename || '(erb)'), 0)
    end
  end
end