[Dovecot] dovecot-lda not logging if dovecot runs under daemontools

[Roberto Puzzanghera]

Hello all,
I have dovecot running under daemontools and I can't see dovecot-lda in 
action when I read the logs.  I've set the logs to /dev/stderr because 
daemontools redirects /dev/stderr to /var/log/dovecot/current.
The dovecot server works fine and I know that dovecot-lda is actually 
doing the delivery, because the sieve facility is working as well. I can 
get lda log working -but only on syslog- if I override the log_path in 
this way:

protocol lda {
mail_plugins = $mail_plugins sieve
log_path =
}

I'm calling dovecot-lda in the usual qmail way. This is my 
.qmail-default:

|/var/qmail/bin/preline -f /usr/libexec/dovecot/deliver -d $EXT@$USER

As running dovecot under daemontools seems to be a common practice among 
qmail users, could any of you give me an hint on how dovecot should be 
configured to achieve the purpose?

Thanks in advance.
My doveconf follows

Roberto Puzzanghera


# dovecof -n

# 2.2.4: /etc/dovecot/dovecot/dovecot.conf
# OS: Linux 3.2.29-smp i686 Slackware 14.0
auth_default_realm = mydomain.net
auth_mechanisms = plain login
auth_socket_path = /var/run/dovecot/auth-userdb
auth_verbose = yes
default_login_user = vpopmail
disable_plaintext_auth = no
first_valid_gid = 89
first_valid_uid = 89
last_valid_gid = 89
last_valid_uid = 89
lda_mailbox_autocreate = yes
lda_mailbox_autosubscribe = yes
log_path = /dev/stderr
mail_access_groups = 89
mail_debug = yes
mail_gid = 89
mail_location = maildir:%h/Maildir
mail_plugins = " quota mail_log notify"
mail_privileged_group = 89
mail_uid = 89
managesieve_notify_capability = mailto
managesieve_sieve_capability = fileinto reject envelope 
encoded-character vacation subaddress comparator-i;ascii-numeric 
relational regex imap4flags copy include variables body enotify 
environment mailbox date ihave spamtest spamtestplus
namespace inbox {
inbox = yes
location =
mailbox Drafts {
auto = subscribe
special_use = \Drafts
}
mailbox Junk {
auto = subscribe
special_use = \Junk
}
mailbox Sent {
auto = subscribe
special_use = \Sent
}
mailbox Trash {
auto = subscribe
special_use = \Trash
}
prefix =
}
passdb {
args = /etc/dovecot/dovecot/conf.d/dovecot-sql.conf.ext
driver = sql
}
plugin {
autocreate = Sent
autocreate2 = Drafts
autocreate3 = Junk
autocreate4 = Trash
autosubscribe = Sent
autosubscribe2 = Drafts
autosubscribe3 = Junk
autosubscribe4 = Trash
mail_log_events = delete undelete expunge copy mailbox_delete 
mailbox_rename
mail_log_fields = uid box msgid size
quota = maildir:User quota
sieve = ~/sieve/dovecot.sieve
sieve_before = /etc/dovecot/sieve/
sieve_dir = ~/sieve
sieve_extensions = +spamtest +spamtestplus +relational 
+comparator-i;ascii-numeric
}
postmaster_address = postmaster@%d
protocols = imap pop3 sieve
sendmail_path = /var/qmail/bin/sendmail
service auth-worker {
user = $default_internal_user
}
service auth {
unix_listener auth-userdb {
group = vchkpw
mode = 0600
user = vpopmail
}
user = $default_internal_user
}
service managesieve-login {
inet_listener sieve {
port = 4190
}
service_count = 1
vsz_limit = 64 M
}
ssl_cert = </etc/dovecot/ssl/certs/dovecot.pem
ssl_key = </etc/dovecot/ssl/private/dovecot.pem
userdb {
args = /etc/dovecot/dovecot/conf.d/dovecot-sql.conf.ext
driver = sql
}
verbose_ssl = yes
protocol lda {
mail_plugins = " quota mail_log notify sieve"
}
protocol imap {
mail_plugins = " quota mail_log notify imap_quota"
}
protocol pop3 {
mail_plugins = " quota mail_log notify"
}