intermittent rspec failure on accessing GCR.cassette

[zben]

Do you have some clue of how I can fix this error? Have you ever seen this? It's not failing on CI and sometimes fail locally.

NoMethodError:
       undefined method `reqs' for nil:NilClass
     # /Users/benz/.rvm/gems/ruby-2.3.1/gems/gcr-1.0.1/lib/gcr/cassette.rb:109:in `request_response'

  def start_playing
    load

    GCR.stub.class.class_eval do
      alias_method :orig_request_response, :request_response

      def request_response(*args)
        req = GCR::Request.from_proto(*args)
        GCR.cassette.reqs.each do |other_req, resp|
          return resp.to_proto if req == other_req
        end
        raise GCR::NoRecording
      end
    end
  end

I think the class_eval magic might have something to do with it.