This is in the CVS version as of Dec. 12. A user got a few of these:
dovecot: Dec 14 15:10:29 Error: 23648 imap(username): mbox sync: UID inserted in the middle of mailbox /mailhome/new/s/h/username/DONE (1591 > 19, seq=19, idx_msgs=1593)
dovecot: Dec 14 15:10:33 Error: 23648 imap(username): file mbox-sync-rewrite.c: line 106 (mbox_sync_headers_add_space): assertion failed: (start_pos < data_size)
dovecot: Dec 14 15:10:40 Error: child 23648 (imap) killed with signal 6
(gdb) bt full #0 0xffffe410 in ?? () No symbol table info available. #1 0xbffff348 in ?? () No symbol table info available. #2 0x00000006 in ?? () No symbol table info available. #3 0x00005c60 in ?? () No symbol table info available. #4 0xb7ef1d41 in raise () from /lib/tls/libc.so.6 No symbol table info available. #5 0xb7ef3529 in abort () from /lib/tls/libc.so.6 No symbol table info available. #6 0x080a17ba in i_internal_panic_handler ( fmt=0x6
, args=0x5c60 ) at failures.c:375 No locals. #7 0x080a1be4 in i_panic ( format=0x80af28c "file %s: line %d (%s): assertion failed: (%s)") at failures.c:173 No locals. #8 0x08074225 in mbox_sync_headers_add_space (ctx=0xbffff6e0, size=4106) at mbox-sync-rewrite.c:99 data_size = Variable "data_size" is not available.(gdb) frame 8 #8 0x08074225 in mbox_sync_headers_add_space (ctx=0xbffff6e0, size=4106) at mbox-sync-rewrite.c:99 99 start_pos = ctx->hdr_pos[MBOX_HDR_X_KEYWORDS] != (size_t)-1 ? (gdb) p start_pos Variable "start_pos" is not available. (gdb) p data_size Variable "data_size" is not available. (gdb) p ctx->hdr_pos[MBOX_HDR_X_KEYWORDS] $1 = 1344 (gdb) p *ctx->header $2 = {data = 0x810d2a0, used = 1395}