I thought I'd keep the subject, as I'm getting a similar (not the same though) error, but in test64 on Linux.
We're using mbox over NFS with mmap turned off. Linux kernel 2.6.
This mailbox is fairly busy.
The logs show: dovecot: Mar 22 19:36:45 Error: 23897 IMAP(support): UIDVALIDITY changed (1111537393 -> 1111538204) in mbox file /mailhome/new/s/support/mbox dovecot: Mar 22 19:36:45 Error: 23897 IMAP(support): file mbox-lock.c: line 511 (mbox_lock): assertion failed: (lock_type == F_RDLCK || ibox->mbox_lock_type != F_RDLCK) dovecot: Mar 22 19:36:45 Error: child 23897 (imap) killed with signal 6
Backtrace: gdb /services/dovecot/libexec/dovecot/imap imap.core.pid23897 GNU gdb 6.2.1 Copyright 2004 Free Software Foundation, Inc. GDB is free software, covered by the GNU General Public License, and you are welcome to change it and/or distribute copies of it under certain conditions. Type "show copying" to see the conditions. There is absolutely no warranty for GDB. Type "show warranty" for details. This GDB was configured as "i586-suse-linux"...Using host libthread_db library "/lib/tls/libthread_db.so.1".
Core was generated by `imap'. Program terminated with signal 6, Aborted.
warning: current_sos: Can't read pathname for load map: Input/output error
Reading symbols from /lib/libdl.so.2...done. Loaded symbols for /lib/libdl.so.2 Reading symbols from /lib/tls/libc.so.6...done. Loaded symbols for /lib/tls/libc.so.6 Reading symbols from /lib/ld-linux.so.2...done. Loaded symbols for /lib/ld-linux.so.2 #0 0xffffe410 in ?? () (gdb) bt #0 0xffffe410 in ?? () #1 0xbffff468 in ?? () #2 0x00000006 in ?? () #3 0x00005d59 in ?? () #4 0xb7ef1d41 in raise () from /lib/tls/libc.so.6 #5 0xb7ef3529 in abort () from /lib/tls/libc.so.6 #6 0x0809513a in i_internal_panic_handler ( fmt=0x6 <Address 0x6 out of bounds>, args=0x5d59 <Address 0x5d59 out of bounds>) at failures.c:374 #7 0x08095554 in i_panic ( format=0x80a138c "file %s: line %d (%s): assertion failed: (%s)") at failures.c:173 #8 0x08069f21 in mbox_lock (ibox=0x80c2e18, lock_type=1, lock_id_r=0xbffff64c) at mbox-lock.c:525 #9 0x0806e279 in mbox_sync (ibox=0x80c2e18, flags=MBOX_SYNC_REWRITE) at mbox-sync.c:1325 #10 0x08067bf9 in mbox_storage_close (box=0x80c2e18) at mbox-storage.c:908 #11 0x0808931d in mailbox_close (box=0x0) at mail-storage.c:297 #12 0x08058f3a in client_destroy (client=0x80b7e40) at client.c:72 #13 0x08059236 in _client_input (context=0x80b7e40) at client.c:387 #14 0x08099eca in io_loop_handler_run (ioloop=0x80b69e8) at ioloop-poll.c:184 #15 0x080995e9 in io_loop_run (ioloop=0x80b69e8) at ioloop.c:218 #16 0x0805fea7 in main (argc=1, argv=0xbffffa24, envp=0xbffffa2c) at main.c:229 (gdb) quit