[fpc-pascal] how to activate debug info

[Giuliano Colla]

Hi fpc team.
When I need to understand how some code works, I frequently use the 
debugger, and single-step.
But when debugging Lazarus applications, I can single-step through user 
code and Lazarus code only, while fpc code is skipped.
I presume that this is happening because my fpc binary is stripped of 
debug information.
In the zillion of compiler options, which are the best ones to provide a 
non-stripped fpc binary?
My environment is Linux, fpc 2.7.1 from svn.

Thanks for any hint

Giuliano