This is a regression due to binding fixes/improvements in 1.1.5. Basically, because we no longer stand up a full frame for invoking "binding", the self is now the caller, rather than the callee. Since binding is private, caller usually is callee; but in a case found in the templater gem, caller is different (using send :binding). Here's a trivial reproduction:
This breaks templater gem, which is used for many things in merb.