MarsSeed [1] filed a deletion request for perl-gtk2-webkit-mechanize [2]: Perl package using gtk2, discontinued in 2009. Nothing on AUR depends on it; on CPAN it has one deprecated dependent EOL'ed after 2011.
I think therefore it's better to delete this package. [1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/perl-gtk2-webkit-mechanize/
