dovecot auth-worker error happens when I enabled the dovecot to consider both the system account and the MySQL virtual mailbox databases.

[Emmanuel Chanel]

Version: 2.2.9 & 2.2.15 ( http://ppa.launchpad.net/malte.swart/dovecot-2.2/ubuntu )
OS: Ubuntu 14.04 Server LTS
I installed Ubuntu 14.04.2 LTS newly on my new server...
And I try to configure the mail server considering both my system account and the virtual mailboxes, by seeing https://www.exratione.com/2014/05/a-mailserver-on-ubuntu-1404-postfix-dovecot-mysql/
But when I configured by uncommenting #!include auth-sql.conf.ext , it doesn't auth...
Possibly, it's a trouble with the configurations of postfix and of dovecot. But I don't understand why...
When I enable either auth-system.conf.ext or auth-sql.conf.ext , it works...

My doveconf -n http://pastebin.com/MU1LL63d
dovecot-sql.conf.ext http://pastebin.com/PJkTnPB3
tail /var/log/mail.log by debug mode / dovecot 2.2.15
http://pastebin.com/1TRQL49d

Mar  6 07:45:12 gateway dovecot: auth: Debug: client
in:
AUTH#0114#011PLAIN#011service=imap#011secured#011session=xS6uSpIQvQDAqAAC#011lip=192.168.0.1#011rip=192.168.0.2#011lport=143#011rport=38333

Mar  6 07:45:12 gateway dovecot: auth: Debug: client passdb out: 
CONT#0114#011
Mar  6 07:45:12 gateway dovecot: auth: Debug: client in: CONT<hidden>
Mar  6 07:45:12 gateway dovecot: auth-worker(22933): Debug: 
pam(emmanuel,192.168.0.2): lookup service=dovecot
Mar  6 07:45:12 gateway dovecot: auth: Error: auth worker: Aborted PASSV 
request for emmanuel: Worker process died unexpectedly
Mar  6 07:45:12 gateway dovecot: auth-worker(22936): Debug: 
sql(emmanuel,192.168.0.2): query: SELECT username as user, password, 
'/home/vmail//emmanuel' as userdb_home, 'maildir:/home/vmail//emmanuel' 
as userdb_mail, 65000 as userdb_uid, 8 as userdb_gid FROM mailbox WHERE 
username = 'emmanuel' AND active = '1'
Mar  6 07:45:12 gateway dovecot: auth-worker(22933): Fatal: master: 
service(auth-worker): child 22933 killed with signal 11 (core dumped)
Mar  6 07:45:12 gateway dovecot: auth-worker(22936): 
sql(emmanuel,192.168.0.2): unknown user
Mar  6 07:45:12 gateway dovecot: auth-worker(23755): Debug: Loading 
modules from directory: /usr/lib/dovecot/modules/auth
Mar  6 07:45:12 gateway dovecot: auth-worker(23755): Debug: Module 
loaded: /usr/lib/dovecot/modules/auth/libdriver_mysql.so
Mar  6 07:45:14 gateway dovecot: auth: Debug: client passdb out: 
FAIL#0114#011user=emmanuel#011temp
Mar  6 07:45:14 gateway dovecot: auth: Debug: client in: 
AUTH#0115#011LOGIN#011service=imap#011secured#011session=xS6uSpIQvQDAqAAC#011lip=192.168.0.1#011rip=192.168.0.2#011lport=143#011rport=38333
Mar  6 07:45:14 gateway dovecot: auth: Debug: client passdb out: 
CONT#0115#011VXNlcm5hbWU6
Mar  6 07:45:14 gateway dovecot: auth: Debug: client in: CONT<hidden>
Mar  6 07:45:14 gateway dovecot: auth: Debug: client passdb out: 
CONT#0115#011UGFzc3dvcmQ6
Mar  6 07:45:14 gateway dovecot: auth: Debug: client in: CONT<hidden>
Mar  6 07:45:14 gateway dovecot: auth-worker(22936): Debug: 
pam(emmanuel,192.168.0.2): lookup service=dovecot
Mar  6 07:45:14 gateway dovecot: auth: Error: auth worker: Aborted PASSV 
request for emmanuel: Worker process died unexpectedly
Mar  6 07:45:14 gateway dovecot: auth-worker(23755): Debug: 
sql(emmanuel,192.168.0.2): query: SELECT username as user, password, 
'/home/vmail//emmanuel' as userdb_home, 'maildir:/home/vmail//emmanuel' 
as userdb_mail, 65000 as userdb_uid, 8 as userdb_gid FROM mailbox WHERE 
username = 'emmanuel' AND active = '1'
Mar  6 07:45:14 gateway dovecot: auth-worker(22936): Fatal: master: 
service(auth-worker): child 22936 killed with signal 11 (core dumped)
Mar  6 07:45:14 gateway dovecot: auth-worker(23755): 
sql(emmanuel,192.168.0.2): unknown user
Mar  6 07:45:14 gateway dovecot: auth-worker(23764): Debug: Loading 
modules from directory: /usr/lib/dovecot/modules/auth
Mar  6 07:45:14 gateway dovecot: auth-worker(23764): Debug: Module 
loaded: /usr/lib/dovecot/modules/auth/libdriver_mysql.so
Mar  6 07:45:16 gateway dovecot: auth: Debug: client passdb out: 
FAIL#0115#011user=emmanuel#011temp
Mar  6 07:45:16 gateway dovecot: auth: Debug: client in: 
AUTH#0116#011PLAIN#011service=imap#011secured#011session=xS6uSpIQvQDAqAAC#011lip=192.168.0.1#011rip=192.168.0.2#011lport=143#011rport=38333#011resp=<hidden>
Mar  6 07:45:16 gateway dovecot: auth-worker(23755): Debug: 
pam(emmanuel,192.168.0.2): lookup service=dovecot
Mar  6 07:45:16 gateway dovecot: auth: Error: auth worker: Aborted PASSV 
request for emmanuel: Worker process died unexpectedly
Mar  6 07:45:16 gateway dovecot: auth-worker(23764): Debug: 
sql(emmanuel,192.168.0.2): query: SELECT username as user, password, 
'/home/vmail//emmanuel' as userdb_home, 'maildir:/home/vmail//emmanuel' 
as userdb_mail, 65000 as userdb_uid, 8 as userdb_gid FROM mailbox WHERE 
username = 'emmanuel' AND active = '1'
Mar  6 07:45:16 gateway dovecot: auth-worker(23755): Fatal: master: 
service(auth-worker): child 23755 killed with signal 11 (core dumped)
Mar  6 07:45:16 gateway dovecot: auth-worker(23764): 
sql(emmanuel,192.168.0.2): unknown user
Mar  6 07:45:16 gateway dovecot: auth-worker(23767): Debug: Loading 
modules from directory: /usr/lib/dovecot/modules/auth
Mar  6 07:45:16 gateway dovecot: auth-worker(23767): Debug: Module 
loaded: /usr/lib/dovecot/modules/auth/libdriver_mysql.so
Mar  6 07:45:18 gateway dovecot: auth: Debug: client passdb out: 
FAIL#0116#011user=emmanuel#011temp

-- 
Emmanuel Chanel( emmanuelchanel at gmail.com )