I've fixed this in Portage for 0.22.5 (stabilization in mind) by simply passing --with-html-dir=/usr/share/doc/${PF}/html to G2CONF, and if you want to support Prefix guys, make that --with-html-dir=${EPREFIX}/usr/share/doc/${PF}/html with EAPI="3". Figured you might want to fix this in your overlay, so you have been informed. :-)
that's nice but a bit too late and there's no vte in overlay.