Multilib difference for usr/lib/ruby/gems/1.8/doc/qpid_proton-0.30.0/ri/Qpid/Proton/cdesc-Proton.yaml on x86_64 vs i686:
--- /usr/lib/ruby/gems/1.8/doc/qpid_proton-0.30.0/ri/Qpid/Proton/cdesc-Proton.yaml on x86_64	2019-12-19 20:52:58.621221408 +0000
+++ /usr/lib/ruby/gems/1.8/doc/qpid_proton-0.30.0/ri/Qpid/Proton/cdesc-Proton.yaml on i686	2019-12-19 20:53:08.106238895 +0000
@@ -13,24 +13,20 @@ class_methods: 
   name: uri
 comment: 
 - !ruby/struct:SM::Flow::P 
-  body: Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file distributed with this work for additional information regarding copyright ownership. The ASF licenses this file to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at
-- !ruby/struct:SM::Flow::VERB 
-  body: "  http://www.apache.org/licenses/LICENSE-2.0\n"
-- !ruby/struct:SM::Flow::P 
-  body: Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.
+  body: Proton is a ruby API for sending and receiving AMQP messages in clients or servers. See the {overview}[../file.README.html] for more.
 constants: 
[...]

Subpackage rubygem-qpid_proton-doc is not multilib-clean for x86_64 vs i686: 200 files have non-equal 32/64bit content:
  /usr/lib/ruby/gems/1.8/doc/qpid_proton-0.30.0/ri/Qpid/Proton/cdesc-Proton.yaml
  /usr/lib/ruby/gems/1.8/doc/qpid_proton-0.30.0/ri/Qpid/Proton/Types/cdesc-Types.yaml
  /usr/lib/ruby/gems/1.8/doc/qpid_proton-0.30.0/ri/Qpid/Proton/Codec/cdesc-Codec.yaml
  /usr/lib/ruby/gems/1.8/doc/qpid_proton-0.30.0/rdoc/index.html
[...]