The screenshot shows that over 3,000 warnings and 1 error prevented the AXF from being built. I guess that the one error was a missing example_lab8.o file. If that's translated from an assembly language file, then I guess that it failed on pre-processor directives and C-style comments embedded in the file.
To fix that, either rename the file to have a .S (capital S) extension or pass the compiler the option -x assembler-with-cpp