Well, it's fair to say "it works in MRI"; $1 being frame-local and thread-local is an exception to the rule, but it is How It Works. JRuby should behave similar

Well, it's fair to say "it works in MRI"; $1 being frame-local and thread-local is an exception to the rule, but it is How It Works. JRuby should behave similarly, full stop.