dovecot - Jan 2013 - assertion failed: (uidmap[src].real_uid == uid)

Hi all,

Does anyone have an idea what could cause the below error?

Dec 31 17:03:46 bobodioulasso dovecot: imap(bla at bla.org): Panic: file 
virtual-sync.c: line 542 (virtual_sync_mailbox_box_remove): assertion 
failed: (uidmap[src].real_uid == uid)
Dec 31 17:03:46 bobodioulasso dovecot: imap(bla at bla.org): Error: Raw 
backtrace: /usr/lib/dovecot/libdovecot.so.0(+0x3c14a) [0x7fe492d1314a] 
-> /usr/lib/dovecot/libdovecot.so.0(+0x3c18e) [0x7fe492d1318e] -> 
/usr/lib/dovecot/libdovecot.so.0(i_fatal+0) [0x7fe492cea81a] -> 
/usr/lib/dovecot/modules/lib20_virtual_plugin.so(+0x9271) 
[0x7fe49169c271] -> 
/usr/lib/dovecot/modules/lib20_virtual_plugin.so(virtual_storage_sync_init+0x160d)
[0x7fe49169dbcd] -> 
/usr/lib/dovecot/libdovecot-storage.so.0(mailbox_sync_init+0x33) 
[0x7fe492fccd43] -> 
/usr/lib/dovecot/libdovecot-storage.so.0(mailbox_sync+0x27) 
[0x7fe492fcce67] -> dovecot/imap(cmd_close+0x71) [0x7fe493484951] -> 
dovecot/imap(command_exec+0x3c) [0x7fe49348c29c] -> 
dovecot/imap(+0x112ee) [0x7fe49348b2ee] -> dovecot/imap(+0x1139a) 
[0x7fe49348b39a] -> dovecot/imap(client_handle_input+0x11d) 
[0x7fe49348b5fd] -> dovecot/imap(client_input+0x65) [0x7fe49348bef5] -> 
/usr/lib/dovecot/libdovecot.so.0(io_loop_call_io+0x36) [0x7fe492d20006] 
-> /usr/lib/dovecot/libdovecot.so.0(io_loop_handler_run+0xa7) 
[0x7fe492d20cb7] -> /usr/lib/dovecot/libdovecot.so.0(io_loop_run+0x28) 
[0x7fe492d1fa18] -> 
/usr/lib/dovecot/libdovecot.so.0(master_service_run+0x13) 
[0x7fe492d0c463] -> dovecot/imap(main+0x297) [0x7fe4934838c7] -> 
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xed) [0x7fe49293976d] 
-> dovecot/imap(+0x9a41) [0x7fe493483a41]
Dec 31 17:03:46 bobodioulasso dovecot: imap(bla at bla.org): Fatal: master: 
service(imap): child 32250 killed with signal 6 (core dumps disabled)

The error only occurs for a single user on the system.  This user uses 
Apple Mail client.

I'm not subscribed to the Dovecot mailing list, so please cc: me on replies.

Regards,
Chris.

---

# dovecot -n

# 2.1.7: /etc/dovecot/dovecot.conf
# OS: Linux 3.2.0-32-generic x86_64 Ubuntu 12.10 ext3
auth_verbose = yes
log_timestamp = "%Y-%m-%d %H:%M:%S "
mail_location = maildir:/var/vmail/%u
mail_privileged_group = mail
maildir_stat_dirs = yes
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
namespace {
   inbox = yes
   location = maildir:/var/vmail/%u
   prefix    separator = .
}
namespace {
   location = virtual:/var/vmail/virtual
   prefix = virtual.
   separator = .
}
passdb {
   args = /etc/dovecot/dovecot-sql.conf
   driver = sql
}
plugin {
   fts = squat
   fts_squat = partial=4 full=10
}
protocols = imap
service auth {
   unix_listener /var/spool/postfix/private/auth-client {
     group = postfix
     mode = 0660
     user = postfix
   }
   unix_listener auth-master {
     group = vmail
     mode = 0600
     user = vmail
   }
   unix_listener auth-userdb {
     group = vmail
     mode = 0600
     user = vmail
   }
}
service imap-login {
   inet_listener imap {
     address = localhost
     port = 143
   }
   inet_listener imaps {
     address = *
     port = 993
   }
}
ssl_cert = </etc/ssl/certs/bobo.crt
ssl_key = </etc/ssl/private/bobo.key
userdb {
   args = uid=5000 gid=5000 home=/var/vmail/%u
   driver = static
}
protocol imap {
   imap_idle_notify_interval = 870 secs
   mail_max_userip_connections = 50
   mail_plugins = fts fts_squat virtual
}
protocol lda {
   mail_plugins = sieve virtual
   postmaster_address = postmaster at bla.org
}

On Thu, 2013-01-03 at 19:13 +0800, Chris Vanden Berghe
wrote:
> Hi all,
> 
> Does anyone have an idea what could cause the below error?
> 
> Dec 31 17:03:46 bobodioulasso dovecot: imap(bla at bla.org): Panic: file 
> virtual-sync.c: line 542 (virtual_sync_mailbox_box_remove): assertion 
> failed: (uidmap[src].real_uid == uid)
Looks like a bug in virtual plugin. Those are a bit difficult to debug
though. It would be very helpful if I could reproduce this myself. I'd
need some files from the user's mailbox for that (not the mail files, so
nothing sensitive). But..:
> The error only occurs for a single user on the system.  This user uses 
> Apple Mail client.
..
> namespace {
>    inbox = yes
>    location = maildir:/var/vmail/%u
>    prefix >    separator = .
> }
> namespace {
>    location = virtual:/var/vmail/virtual
>    prefix = virtual.
>    separator = .
> }
This isn't a good setup. Now each user recreates the entire virtual
mailbox every time it's opened. Maybe the bug is related to that. Use
instead something like:

namespace {
  location = virtual:/var/vmail/virtual:INDEX=/var/vmail/%u/virtual