status codes on exit:
=====================

-8 = mixed backend errors (combo of -3, -4, -5, -6, -7 errors type)
-7 = backend error: Invalid module_extra_buffer_size
-6 = backend error: Too many compute units to keep minimum kernel accel limit
-5 = backend error: main kernel build error
-4 = backend error: memory hit
-3 = backend error: skipping hash-type due to module_unstable_warning settings
-2 = gpu-watchdog alarm
-1 = error
 0 = OK/cracked
 1 = exhausted
 2 = aborted
 3 = aborted by checkpoint
 4 = aborted by runtime