Unexpected result from "geli attach" attempt

TL;DR: I attempted "/sbin/geli attach -k - /dev/ada0s4j"; result was:
	geli: Invalid value for 'n' argument: Result too large

Background: Yesterday afternoon (UTC-0700), a colleague ... mentioned
... thaht after updating a machine to [that] morning's -current, he was
unable to use the Yubikey (that work requires for authentication).

While I had updated some machines that day, I had not attempted to do
much more than an initial "smoke-test" for head/current -- I normally
depend on stable (and had updated stable/14, which was working).

So after today's update, I thought I would test the Yubikey under head.

So after having updated my laptop from main-n279413-8ae1d55bfcd0 to
main-n279471-f4744b8acb93 (which is now called "15.0-PRERELEASE" instead
of "15.0-CURRENT"), I needed to mount the (GELI-encrypted) file system
on my laptop that I use for work-related stuff.

This is something that I have done sufficiently often that it's nearly
all "muscle memory" ... in stable/14 (and earlier, in stable/12 and
stable/11; probably stable/10, as well, but I wouldn't swear to it).

So getting that response from the attempt was ... surprising.  And I
found the response singularly unhelpful: I have no idea what the source
of the complaint is.

I see in the code (in src/sbin/geom/core/geom.c, So after having updated
my laptop from main-n279413-8ae1d55bfcd0 to
main-n279471-f4744b8acb93 (which is now called "15.0-PRERELEASE" instead
of "15.0-CURRENT"), I needed to mount the (GELI-encrypted) file system
on my laptop that I use for work-related stuff.

This is something that I have done sufficiently often that it's nearly
all "muscle memory" ... in stable/14 (and earlier, in stable/12 and
stable/11; probably stable/10, as well, but I wouldn't swear to it).

So getting that response from the attempt was ... surprising.  And I
found the response singularly unhelpful: I have no idea what the source
of the complaint is.

I see (in src/sbin/geom/core/geom.c, in set_option()) that the message
is emitted from:

        if (G_OPT_TYPE(opt) == G_TYPE_NUMBER) {
                if (expand_number(val, &number) == -1) {
                        err(EXIT_FAILURE, "Invalid value for '%c' argument",
                            opt->go_char);
                }

May I please have the use of a clue?

Peace,
david
-- 
David H. Wolfskill                              david@catwhisker.org
Of course firing the statistician will force the statistics to conform!

See https://www.catwhisker.org/~david/publickey.gpg for my public key.