YESSS !!! it works
Thanks you very much @Martin_fr, @Thaddy
My conclusion is, the only needed steps are:
1. recompile rtl with debug mode. (for me -gw3 is solving)
2. assuring that the compiled fpc is accessible by lazarus.
The second step was (as noticed earlier by martin) : complicated things in linux.
Long live FreePascal Long live Lazarus