Seen twice on lindsay.d.o in the last 24 hours. The exact reason is
unknown, but it is probably during the unpacker (last non-error in the
log is lintian starting the unpack, plus previously we had a race-condition
in the unpacker that could trigger a similar fork-bomp situation).
Most likely we never fixed this condition and only made it
"sufficiently unlikely" until gcc-8-cross-ports showed up.
For now, I have disabled the crontab on lindsay.d.o to avoid it taking
down our host.