Comment # 5 on bug 910343 from Martin Vidner

`set_trace_func` together with `caller` should do the trick:

-- trace.rb
require "yast"

set_trace_func proc { |event, file, line, id, binding, classname|
  unless ["c-call", "c-return", "line"].include? event
    if classname.to_s == "Yast::UI"
      m = "#{classname}.#{id}"
      printf "%8s %s:%-2d %s\n", event, file, line, m
    end
  end
}

Yast::WFM.CallFunction(Yast::WFM.Args(0), [])
--

/sbin/yast2 ./trace.rb bootloader