So, I was able to make test with bleadperl on Mac OS X with zero errors. This apparently surprised Jarkko, among others, since (I presume) nobody's been able to get DB_File to work. ('Twas super-easy. I installed the most recent version of Berkeley DB, and things Just Worked.)
Schwern told me to tell p5p, so I finally took the plunge and joined the mailing list. This has been the high point of my weekend.