dev-perl/Authen-SASL-2.10 contains GSSAPI support. It requires GSSAPI.pm which doesn't have it's portage package. An ebuild for GSSAPI generated by g-cpan works well. It should be added to portage and Authen-SASL should depend on it conditionally (kerberos USE flag). Reproducible: Always
Created attachment 127846 [details] GSSAPI ebuild (by g-cpan)
Created attachment 127848 [details] Authen-SASL ebuild withGSSAPI dependency
Added dev-perl/GSSAPI and dev-perl/Authen-SASL-2.10-r1 with conditional dependency. Thanks for bringing this up!