[Dovecot] Dovecot-2.1.14 - pop3 processes always hangs forever

Hello,

I'm currently experimenting with the 2.1.x series and am facing a behavior I can't explain; I must be doing something wrong and probably miss the obvious... ;-)

This is a very basic build on Mac OS X 10.8.2:

./configure --prefix=/_COD/dovecot-2.1.14 --sysconfdir=/_ETC --localstatedir=/_VAR --with-sqlite --with-ldap=yes

(Yes, I know, a strange layout, yet very convenient for testing various things here.)

Dovecot's configuration is very basic too:

# 2.1.14: /_ETC/dovecot/dovecot.conf
# OS: Darwin 12.2.1 x86_64  
auth_verbose = yes
disable_plaintext_auth = no
mail_debug = yes
mail_location = mbox:~/mboxes:INBOX=~/mboxes/inbox
passdb {
  args = /_ETC/dovecot/db.conf
  driver = sql
}
ssl = no
userdb {
  driver = prefetch
}

It is started from launchd with the -F flag.

Two users are defined in the database, user1 (100002/100002) and user2 (100003/100003), with "virtual" uids/gids.

Connecting for the first time as user1 through imap:

$ telnet 127.0.0.1 143
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
* OK [CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE IDLE AUTH=PLAIN] Dovecot ready.
a login user1 pass1
a OK [CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE IDLE SORT SORT=DISPLAY THREAD=REFERENCES THREAD=REFS THREAD=ORDEREDSUBJECT MULTIAPPEND UNSELECT CHILDREN NAMESPACE UIDPLUS LIST-EXTENDED I18NLEVEL=1 CONDSTORE QRESYNC ESEARCH ESORT SEARCHRES WITHIN CONTEXT=SEARCH LIST-STATUS SPECIAL-USE] Logged in
b logout
* BYE Logging out
b OK Logout completed.
Connection closed by foreign host.

In mail.log:

dovecot[2997]: imap-login: Login: user=<user1>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=3006, secured, session=<EOWWzjbVxQB/AAAB>
dovecot[2997]: imap(user1): Debug: Effective uid=100002, gid=100002, home=/_Data/Mailstores/100002
dovecot[2997]: imap(user1): Debug: Home dir not found: /_Data/Mailstores/100002
dovecot[2997]: imap(user1): Debug: fs: root=/_Data/Mailstores/100002/mboxes, index=, control=, inbox=/_Data/Mailstores/100002/mboxes/inbox, alt=
dovecot[2997]: imap(user1): Debug: Namespace : /_Data/Mailstores/100002/mboxes doesn't exist yet, using default permissions
dovecot[2997]: imap(user1): Debug: Namespace : Using permissions from /_Data/Mailstores/100002/mboxes: mode=0700 gid=-1
dovecot[2997]: imap(user1): Disconnected: Logged out in=8 out=362

While logged in (ie after the login and before the logout), "doveadm who" shows:

username # proto (pids) (ips)                                                                         
user1    1 imap  (3093) (127.0.0.1)                                                                   

So far, so good.

Now, let's connect as user2 for the first time, through pop:

$ telnet 127.0.0.1 110
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
+OK Dovecot ready.
user user2
+OK
pass pass2

and the session hangs forever.

This is written in the log:

dovecot[2997]: pop3-login: Login: user=<user2>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=3113, secured, session=<GTOlMjfV3gB/AAAB>
dovecot[2997]: pop3(user2): Debug: Effective uid=100003, gid=100003, home=/_Data/Mailstores/100003
dovecot[2997]: pop3(user2): Debug: Home dir not found: /_Data/Mailstores/100003
dovecot[2997]: pop3(user2): Debug: fs: root=/_Data/Mailstores/100003/mboxes, index=, control=, inbox=/_Data/Mailstores/100003/mboxes/inbox, alt=
dovecot[2997]: pop3(user2): Debug: Namespace : /_Data/Mailstores/100003/mboxes doesn't exist yet, using default permissions
dovecot[2997]: pop3(user2): Debug: Namespace : Using permissions from /_Data/Mailstores/100003/mboxes: mode=0700 gid=-1
dovecot[2997]: pop3(user2): Debug: Namespace : /_Data/Mailstores/100003/mboxes/inbox doesn't exist yet, using default permissions
dovecot[2997]: pop3(user2): Debug: Namespace : Using permissions from /_Data/Mailstores/100003/mboxes: mode=0700 gid=-1
dovecot[2997]: pop3(user2): Debug: Namespace : /_Data/Mailstores/100003/mboxes/inbox doesn't exist yet, using default permissions
dovecot[2997]: pop3(user2): Debug: Namespace : Using permissions from /_Data/Mailstores/100003/mboxes: mode=0700 gid=-1

while "doveadm who" pretends nobody is connected:

username # proto (pids) (ips)                                                                      

To get rid of the pop3 process, I have to send it a KILL signal: no other way. But this is noticed by the master process:

dovecot[2997]: pop3(user2): Fatal: master: service(pop3): child 3113 killed with signal 9

Note that it is possible to connect afterwards as user2 through imap. On the other hand, trying to connect as user1 or user2 through pop always hangs.

TIA, Axel