Was it intended that the po plugin add a new dependency?

    PERL5LIB=.. ./po2wiki underlay.setup
    Failed to load plugin IkiWiki::Plugin::po: Can't locate Locale/Po4a/Common.pm in @INC (@INC contains: .. /Library/Perl/Updates/5.8.8 /System/Library/Perl/5.8.8/darwin-thread-multi-2level /System/Library/Perl/5.8.8 /Library/Perl/5.8.8/darwin-thread-multi-2level /Library/Perl/5.8.8 /Library/Perl /Network/Library/Perl/5.8.8/darwin-thread-multi-2level /Network/Library/Perl/5.8.8 /Network/Library/Perl /System/Library/Perl/Extras/5.8.8/darwin-thread-multi-2level /System/Library/Perl/Extras/5.8.8 /Library/Perl/5.8.6 /Library/Perl/5.8.1 /sw/lib/perl5/5.8.8/darwin-thread-multi-2level /sw/lib/perl5/5.8.8 /sw/lib/perl5/darwin-thread-multi-2level /sw/lib/perl5 /sw/lib/perl5/darwin /usr/local/lib/perl5/site_perl/5.8.8/darwin-thread-multi-2level /usr/local/lib/perl5/site_perl/5.8.8 /usr/local/lib/perl5/site_perl .) at ../IkiWiki/Plugin/po.pm line 13.
    BEGIN failed--compilation aborted at ../IkiWiki/Plugin/po.pm line 13.
    Compilation failed in require at (eval 27) line 2.
    BEGIN failed--compilation aborted at (eval 27) line 2.
    
    make[1]: *** [po2wiki_stamp] Error 2
    make: *** [extra_build] Error 2