I believe that in dovecot-2.x the berkdb is non-functional. The ebuild still mentions berkdb as possible use-flag. I think that this USE-flag should be removed. Reproducible: Always
+ 09 May 2011; Eray Aslan <eras@gentoo.org> dovecot-2.0.12-r2.ebuild: + Remove useless berkdb USE flag bug #366481 +