I'm doing a (belated) update from a version before emailauth was available, and I get the error:

Failed to load plugin IkiWiki::Plugin::emailauth: Not enough arguments for IkiWiki::cgi_getsession

and sure enough, emailauth.pm line 175 has

my $session=IkiWiki::cgi_getsession();

while cgi_getsession is declared in CGI.pm as

sub cgi_getsession ($) {
    my $q=shift;

and browsing through git history, it looks like it has always been that way. Now, I have some local mods merged in, so it is possible one of them has broken something, but before I begin questioning my sanity, just by looking at these lines in the unmodified ikiwiki repo, um, has this ever worked? And, why?