-mdeb ran into a null pointer, hence applied the following fix.
http://gcc.gnu.org/r217651 Johann gcc/ * config/avr/avr-log.c (avr_log_set_avr_log) [TARGET_ALL_DEBUG]: Set avr_log_details to "all". Index: avr-log.c =================================================================== --- avr-log.c (revision 217649) +++ avr-log.c (working copy) @@ -316,6 +316,9 @@ avr_log_set_avr_log (void) { bool all = TARGET_ALL_DEBUG != 0; + if (all) + avr_log_details = "all"; + if (all || avr_log_details) { /* Adding , at beginning and end of string makes searching easier. */