This ebuild has an incorrect dependency on perl-CGI 3.19. This version of CGI causes the configuire script to crash and makes twiki unusable. Solution looks like a rollback to a prior CGI version or an update to perl-CGI 3.20 see http://twiki.org/cgi-bin/view/Support/InstallationProblemWithConfigure
Ebuild doesn't have a dependency on any particular CGI version, just read it.
Noted, have asked the perl folks to bump CGI to 3.20
CGI bumped. ~Perly Folks
fixed in CVS