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 <addr> <count> -- dump memory
u <addr>         -- dump object at tagged <addr>
. <addr>         -- print object at tagged <addr>
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 <addr>      -- find data heap references to object
push <addr>      -- push object on data stack - NOT SAFE
code             -- code heap dump
READY
Nursery: Start=7f367d500000, size=200000, end=7f367d700000
Aging: Start=7f367cd00000, size=400000, end=7f367d100000
Tenured: Start=7f3670d00000, size=c000000, end=7f367cd00000
Cards:base=7f3670c0d010, size=ca400
READY