Developing the Sonix Firmware: Cannot change configUSE_TRACE_FACILITY from 0 to 1

First I am grateful for this list of instructions so graciously provided in the documentation for building the Sonix firmware:
git clone
cd Sonix/buildscript
git submodule update --init --recursive
make oldconfig
make clean && make mavlink && make && make install
ls -l …/image/dashcam/FIRMWARE_660R.bin

I was able to build the Sonix firmware in Ubuntu 16.04 after fixing two things in my build environment:

  1. sudo apt-get install zlib1g:i386 //rectifies the following make error
    error while loading shared libraries: cannot open shared object file: No such file or directory
  2. cpan Encode::Detect::Detector && cpan Digest::CRC //Perl modules needed by ‘make install’

Following the very nicely provided build instructions I do indeed get a new ./image/dashcam/FIRMWARE_660R.bin along with quite a few new .bin files. Many thanks for that documentation.

Now I come to my issue: I cannot change configUSE_TRACE_FACILITY from 0 to 1 in the FreeRTOSConfig.h file. There’s a bit of history associated with the configUSE_TRACE_FACILITY so my usage of it might be doomed to failure. But my point is it seems to automatically revert back to 0 when after I change it to 1 and ‘make’ && ‘make install’

My goal is to use gdb to single step through code on the Sky Viper v2450GPD hardware (Flight controller and/or Sonix board). Maybe, I’m going about it all wrong. I don’t mind experimenting and reporting my results. I am grateful to @tridge for his very helpful “Flight Board Hacking” post that enabled me to get access to the “debug console” on the Flight controller board. But I’m still basically in the dark on how to single step through code on the Sky Viper using gdb.

UPDATE: I am optimistic to use gdb debugger for single stepping through Ardupilot code on Sky Viper hardware using the Black Magic Probe mentioned here

QUESTION: Is anyone else using a Black Magic Probe with Sky Viper?