find it in /bin. This is something of a kludge, I know, but consider
my limited alternatives: I can't make this an execvp() without making
people scream that I introduced a failure point or slowed down pwd,
and I can't make it an optional macro since crunch doesn't let you pass
arbitrary command-line args to the build of one of its crunch-ees.
This is the simplest, if not the nicest looking, solution I could come up
with.
