I have been searching for 2 days how to dump core files in Harmattan while running apps on device but couldn't find. (kill -sigsegv <pid> => does not seems to dump the core)

the only link for info i managed to find seems to skip the "on device core dump" and only mention it in scratchbox: http://harmattan-dev.nokia.com/docs/...cratchbox.html
on the n900 it was simple (install sp-rich-core)

I have rechecked and my app is compiled with the debug flags.

Does anyone know how it should be done? or encountered a similar behavior?

Diablo and Fremantle both use /proc/sys/kernel/core_pattern . Maybe Harmattan does, too. See core(5) or e.g. http://linux.die.net/man/5/core for usage.