The die word was called by the library. Unless you called it yourself, you have triggered a bug in Factor. Please report. Starting low level debugger... Basic commands: q -- continue executing Factor - NOT SAFE im -- save image to fep.image x -- exit Factor Advanced commands: d -- dump memory u -- dump object at tagged . -- print object at tagged t -- toggle output trimming s r -- dump data, retain stacks .s .r .c -- print data, retain, call stacks e -- dump environment g -- dump generations data -- data heap dump words -- words dump tuples -- tuples dump refs -- find data heap references to object push -- push object on data stack - NOT SAFE code -- code heap dump READY 00000000010ee470: 0000000000000001 tag 1 00000000010ee478: 0000000000000001 tag 1 00000000010ee480: 0000000000000001 tag 1 00000000010ee488: 0000000000000001 tag 1 00000000010ee490: 0000000000000001 tag 1 00000000010ee498: 00007fba9c0a4404 tag 4 00000000010ee4a0: 00007fba9c0a443b tag 11 00000000010ee4a8: 0000000000000080 tag 0 00000000010ee4b0: 00007fbaa88800c6 tag 6 00000000010ee4b8: 00007fbaa88800f6 tag 6 00000000010ee4c0: 00007fbaa8880182 tag 2 00000000010ee4c8: 00007fbaa8880036 tag 6 00000000010ee4d0: 00007fbaa8880066 tag 6 00000000010ee4d8: 00007fbaa8880006 tag 6 00000000010ee4e0: 00007fbaa8880126 tag 6 00000000010ee4e8: 0000000000000001 tag 1 00000000010ee4f0: 0000000000000001 tag 1 00000000010ee4f8: 0000000000000001 tag 1 00000000010ee500: 0000000000000001 tag 1 00000000010ee508: 0000000000000001 tag 1 00000000010ee510: 00007fba9c135e64 tag 4 00000000010ee518: 00007fba9c15cbd7 tag 7 00000000010ee520: 00007fba9c0b63b4 tag 4 00000000010ee528: 00007fba9c0b6332 tag 2 00000000010ee530: 00007fba9c08d6ac tag 12 00000000010ee538: 00007fba9c0b6b12 tag 2 00000000010ee540: 00007fba9c0b6d12 tag 2 00000000010ee548: 00007fba9c0b6a92 tag 2 00000000010ee550: 00007fba9c0aa60c tag 12 00000000010ee558: 00007fba9c0b6152 tag 2 00000000010ee560: 00007fba9c0b6a12 tag 2 00000000010ee568: 00007fba9c0b6c42 tag 2 00000000010ee570: 00007fba9c0b69c2 tag 2 00000000010ee578: 00007fba9c0b61d2 tag 2 00000000010ee580: 00007fba9c0ab72c tag 12 00000000010ee588: 00007fba9c0b60f2 tag 2 00000000010ee590: 00007fba9c0aa59c tag 12 00000000010ee598: 00007fba9c0b6082 tag 2 00000000010ee5a0: 00007fba9c0a9a1c tag 12 00000000010ee5a8: 00007fba9c0b6bf2 tag 2 00000000010ee5b0: 00007fba9c0b6a52 tag 2 00000000010ee5b8: 00007fba9c08d5fc tag 12 00000000010ee5c0: 00007fba9c08e29c tag 12 00000000010ee5c8: 00007fba9c08dc3c tag 12 00000000010ee5d0: 00007fba9c08d4ac tag 12 00000000010ee5d8: 00007fba9c08d90c tag 12 00000000010ee5e0: 00007fba9c08e0fc tag 12 00000000010ee5e8: 0000000000000820 tag 0 00000000010ee5f0: 00007fba9c0b6282 tag 2 00000000010ee5f8: 00007fba9c0b6962 tag 2 00000000010ee600: 00007fba9c0b6cd2 tag 2 00000000010ee608: 00007fba9c0b6b72 tag 2 00000000010ee610: 00007fba9c0b6c82 tag 2 00000000010ee618: 00007fba9c0b6ea2 tag 2 00000000010ee620: 00007fba9c0b6912 tag 2 00000000010ee628: 00007fba9c0abc5c tag 12 00000000010ee630: 00007fba9c0abdec tag 12 00000000010ee638: 00007fba9c0b6db2 tag 2 00000000010ee640: 00007fba9c0aba5c tag 12 00000000010ee648: 00007fba9c0ab9ec tag 12 00000000010ee650: 00007fba9c08b2a4 tag 4 00000000010ee658: 00007fbaa8880096 tag 6 00000000010ee660: 00007fba9c08ba7c tag 12 00000000010ee668: 0000000000000001 tag 1 00000000010ee670: 0000000000000001 tag 1 00000000010ee678: 0000000000000001 tag 1 00000000010ee680: 0000000000000001 tag 1 00000000010ee688: 00007fbaa8880156 tag 6 00000000010ee690: 0000000000000001 tag 1 00000000010ee698: 0000000000000001 tag 1 READY