• JRuby version: 9.1.7.0
• Linux 2.6.32-642.6.2.el6.x86_64 break script engine #1 SMP Wed Oct 26 06:52:09 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux

Saw this appear in our exception monitoring: org.jruby.runtime.scopes.DynamicScope1 only supports scopes with 1 variables

The code in question that fails looks something like this:

items.each do |item|
  foo = item.foo
  some_helper_method foo
end 

where items is a Java collection. Failure happens while trying to evaluate the block (JavaLang.each is the first Java line in the call stack).

From the logs it looks like the same call site will keep failing with that exception until the app is restarted, so guessing either the call site or DynamicScope1 is in a bad state. I'll note that this is happening in the same jobs that caused me to file an issue about another race condition during DynamicScope generation last year, so this might be related to that.

I'm gonna be digging into this issue, but would love to see if anyone has any ideas.