Debugging with printf...

have you tried fprintf(stderr, "message")?
flushes (prints) to stderr (console, error channel) as soon as called

https://stackoverflow.com/questions...

Is there another way?

@rittmann im no authority in the matter, but usually thats how i debug.
printf's everywhere + valgrind to detect leaks + gdb to look at the asm(more for opti than anything else).
i dump to bmp if i muck around with cv.
otherwise i dump to text. usually i redirect in the console thence the fprintfs.
otherwise test driven development (test veery often)