$ ./ttyleak7 500
pre-created 501 colliding node names
iter 0..499: UNEXPECTED success (counter state -> no collisions this run)
TTYLEAK-DONE 500 failed TIOCSETD opens
$ vmstat -m | grep netgraph
  netgraph  804  98.9K ... (live-state growth from successful opens)
$ dmesg | tail
tty500: node name exists?      <-- ng7 error branch IS reachable
tty501: node name exists?