Sieve logging?

I am trying to create some sieve scripts to filter my mailing lists and am wondering if sieve logs anywhere, and it so where? I don’t see anything in mail.log beyond lines like:

dovecot: lda(kremels@kreme.com)<39790><hNchChSkAV1umwAAIdGjjQ>: sieve: msgid=267D5D71-D99C-4790-8706-C1A92BCC9F97@kreme.com: stored mail into mailbox ‘INBOX'

Which doesn’t really tell me anything other than that the script failed.

-- If the #2 pencil is the most popular, why is it still #2?