I'm seeing core-dumps with both 2.0-beta4 and a fresh checkout from Mercurial. I'm very new to Dovecot, so there's a good chance this is caused by my limited experience with Dovecot configuration, but it's my understanding that any core-dump is considered a bug (nice policy by the way).
The installation seemed to be working as expected until I added the two namespaces and tried to set up shared mailboxes.
Timo: The installation is running on a KVM dedicated to testing Dovecot, so if you want to debug anything in my environment, just send me your SSH key, and I'll set it up.
Attached files (from test with latest Mercurial):
dialog.txt: IMAP dialogue to reproduce the core dump mail.info.txt: Resulting log entries debug.log.txt: Resulting debug-log entries bt-full.txt: br full for dumped core dovecot-n.txt: Output of dovecot -n sql.txt: passdb/userdb SQL configuration
-- Regards B. Johannessen