Monitoring a process which was exec'd using the -c switch.
$ pfexec dtrace -n 'profile-97/pid == $target && arg1/{@[jstack(100, 8000)] = count(); } tick-60s { exit(0); }' -c node
dtrace: description 'profile-97' matched 2 probes
> dtrace: pid 79919 has exited
node`ares__read_line
node`_ZN4node10cares_wrapL10InitializeEN2v86HandleINS1_6ObjectEEE+0x6a