Issue with JRuby

[bryanvpham]

Used protoc to generate at.rb. My main.rb literally just includes at.rb and outputs "hello world".

I built the gem from scratch following the instructions in the readme. Tried running my simple ruby program that

RuntimeError: headers.key: "key" is already defined in "headers".
    build at com/google/protobuf/jruby/RubyDescriptorPool.java:84
   <main> at /root/work/at/at.rb:6
  require at org/jruby/RubyKernel.java:955
   (root) at uri:classloader:/jruby/kernel/kernel.rb:1
   <main> at main.rb:1

[liujisi]

My impression is Jruby is currently broken and not maintained by anyone.. Adding @haberman for more info.

[felixcuello]

The workaround I found (for now) is to rename map structures and have unique names for all of them. Because as soon as I repeat the map name we get the exact same error.

[mjmateuci]

Do you guys found another way to solve this issue? @bryanvpham @pherl

[headius]

JRuby has been continuously maintained for over ten years and is still in very active use at many organizations. Can we get this fixed?

[acozzette]

At the moment I don't think we have anyone working on protobuf who is knowledgeable about JRuby unfortunately, but we would be glad to accept pull requests with fixes.

[jthack]

Pretty crazy this issue is still around.

[haberman]

I believe this is fixed in #7923.