Exits with a non-zero status if there were any processing errors. Having no fonts present counts as a processing error.
If there is at least one font present, then missing fonts will be
replaced by the first cmr10 font it finds, or a more-or-less
randomly chosen alternative if that font is not used at all. The
program will produce a warning if the -q option is not present,
but it will return with a zero (success) status.
Exception: If the -n option (see Section 2.1) is
present, then the program returns success only if all fonts are present.