#0  0x00002b20f4d46ed5 in raise () from /lib/libc.so.6
#1  0x00002b20f4d483f3 in abort () from /lib/libc.so.6
#2  0x00002b20f48f4cdc in objc_exception_throw () from /usr/lib/libobjc.so.2
#3  0x00002b20f3ac6631 in ?? () from /usr/lib/libgnustep-base.so.1.16
#4  0x00002b20f3ac60fa in ?? () from /usr/lib/libgnustep-base.so.1.16
#5  0x00002b20f3ac604d in ?? () from /usr/lib/libgnustep-base.so.1.16
#6  0x00002b20f3bb7b23 in ?? () from /usr/lib/libgnustep-base.so.1.16
#7  0x00002b20f6a6ab84 in __vacall_r () from /usr/lib/libcallback.so.0
#8  0x00000000004049d7 in main (argc=1, argv=0x7fffb7e1b3b8) at spiral.m:342