The issue occurs if ENABLE_FEATURE_CROND_D is NOT set. In that case PARSE_KEEP_COPY is set to 0. Which results in parser->data being a nullptr. Stacktrace #0 skip_whitespace (s=0x0) at libbb/skip_whitespace.c:19 #1 0x0000aaaaafef12f8 in load_crontab () at miscutils/crond.c:517 #2 0x0000aaaaafef1588 in rescan_crontab_dir () at miscutils/crond.c:634 #3 0x0000aaaaafef1880 in crond_main () at miscutils/crond.c:1056 #4 0x0000aaaaafee3130 in run_applet_no_and_exit () at libbb/appletlib.c:967 #5 0x0000aaaaafee34c0 in run_applet_and_exit () at libbb/appletlib.c:986 #6 0x0000aaaaafee3550 in main (argc=<optimized out>, argv=0xffffcb7f5668) at libbb/appletlib.c:1126