Obtaining global unit method names from pointers

[JernejL]

Code: Pascal  [Select][+][-]

1.     showmessage(BackTraceStrFunc(@registerguipointer));
2.  
3.     GetLineInfo(longword(@registerguipointer), tfunc, tsource, iline);
4.  
5.     showmessage(tsource);
6.  

Neither will return actual function name in that pointer.
 

$00439B00 line 278 of game_Gui.pas

with GetLineInfo:

tfunc = ''
tsource = 'game_gui.pas'
 
I'm running this on lazarus 1.8.0 rc5 and fpc 3.0.4. debug symbols are dwarf2 with nearly all debug data options on, i've gone thru all the documentation on http://wiki.freepascal.org/Logging_exceptions and can't find a way to get unit procedure names from pointer, what else is availible?