Continuing to process had the unintended effect that `man` failed to find
a matching manual page for {EMPTY LIST OF REQUESTED MANUAL PAGES}, and
exited with 1.
Prompted by a fish shell snippet that tried and failed to distinguish between
FreeBSD man (-p takes argument) and NetBSD man (-p no argument) by comparing
`man -p` exit code.
ok riastradh, logix (which also pointed out the manual page SYNOPSIS is
saying man -p should be used this way).