debug stack level too deep error in ruby

stack_level_too_deep_debug.rb

# found here:
# http://stackoverflow.com/a/28680027/1488217

set_trace_func proc {
  |event, file, line, id, binding, classname| 
  if event == "call"  && caller_locations.length > 500
    fail "stack level too deep"
  end
}