killall -SIGNAL does not work for almost all signals in psmisc 23.2

killall -HUP foo and the like are almost all broken in psmisc 23.2.

killall (PSmisc) 23.2

$ for SIG in $(killall -l) ; do echo -n "$SIG " ; killall -${SIG} foo 2>&1 | head -n1 ; done | egrep -v Usage
INT foo: no process found
ILL foo: no process found
$

And none work in -SIG${SIG} form.

In psmisc 23.1, all signals except -INT, -ILL, and -VTALRM behaved as expected in short form, and all work with -SIG${SIG}.

From changelogs & git blame it looks to me like argument processing was extensively reworked recently; closed issue #11 (closed) fixed INT and perhaps ILL as a side effect. killall(1) still lists -SIGNAL as being supported (not to mention a big POLA violation if it went away), so I hope this is just an oversight.