I think mail-filter/spamassassin-3.1.3 should depend on perl-core/DB_File.
emerge --depclean removed DB_File from my system, but I had to emerge it manually because Bayes filter didn't work anymore with spamassassin.
PS : Sorry for my bad english.
It already depends on virtual/DB_File w/ USE=berkdb, that's a correct one.
Ok, sorry, I should search in RESOLVED/INVALID bugs (#81867). I have -berkdb in my USES.
Well, if you have -berkdb, then this functionality won't be available, that's intended. If you compile perl w/ USE=berkdb, then you don't need perl-core/DB_File as it's already included in perl. So, nothing to fix here.
I re-emerged spamassassin, perl, and libperl (spamassassin wasn't sufficient) with USE berkdb and it works now.
Sorry for all the noise.