[Dovecot] Crash in dsync [dovecot 2.1.7]

[Joe Beaubien]

Just taught i'd report this crash while running the ofllowing command:

19748 Aborted                 (core dumped) $DSYNC_BINARY -f -u document
backup mdbox:$LOCAL_BACKUP_PATH/emails/document >> $LOG_FILE 2>&1


Here is the traceback I got:

dsync(document): Error: Mailbox INBOX/Julie: Corrupted index, uidvalidity=0
dsync(document): Warning: mdbox
/backup_hdd/current/emails/document/storage: rebuilding indexes
dsync(document): Panic: file mdbox-storage-rebuild.c: line 66
(mdbox_storage_rebuild_init): assertion failed:
(!storage->rebuilding_storage)
dsync(document): Error: Raw backtrace:
/opt/dovecot-2.1.7/lib/dovecot/libdovecot.so.0(+0x4203a) [0x7faa3bbde03a]
->
/opt/dovecot-2.1.7/lib/dovecot/libdovecot.so.0(default_fatal_handler+0x2a)
[0x7faa3bbde0fa] ->
/opt/dovecot-2.1.7/lib/dovecot/libdovecot.so.0(i_fatal+0) [0x7faa3bbb53f0]
->
/opt/dovecot-2.1.7/lib/dovecot/libdovecot-storage.so.0(mdbox_storage_rebuild_in_context+0x117e)
[0x7faa3be656de] ->
/opt/dovecot-2.1.7/lib/dovecot/libdovecot-storage.so.0(mdbox_sync_begin+0x23a)
[0x7faa3be62b1a] ->
/opt/dovecot-2.1.7/lib/dovecot/libdovecot-storage.so.0(mdbox_sync+0x33)
[0x7faa3be630f3] ->
/opt/dovecot-2.1.7/lib/dovecot/libdovecot-storage.so.0(mdbox_storage_sync_init+0x7e)
[0x7faa3be631be] ->
/opt/dovecot-2.1.7/lib/dovecot/libdovecot-storage.so.0(mailbox_sync_init+0x31)
[0x7faa3bea2871] ->
/opt/dovecot-2.1.7/lib/dovecot/libdovecot-storage.so.0(mailbox_sync+0x27)
[0x7faa3bea2997] ->
/opt/dovecot-2.1.7/lib/dovecot/libdovecot-storage.so.0(mailbox_mark_index_deleted+0x9b)
[0x7faa3bea3aeb] ->
/opt/dovecot-2.1.7/lib/dovecot/libdovecot-storage.so.0(mailbox_open+0x85)
[0x7faa3bea3a25] ->
/opt/dovecot-2.1.7/lib/dovecot/libdovecot-storage.so.0(mdbox_storage_rebuild_in_context+0xb7b)
[0x7faa3be650db] ->
/opt/dovecot-2.1.7/lib/dovecot/libdovecot-storage.so.0(mdbox_sync_begin+0x23a)
[0x7faa3be62b1a] ->
/opt/dovecot-2.1.7/lib/dovecot/libdovecot-storage.so.0(mdbox_sync+0x33)
[0x7faa3be630f3] ->
/opt/dovecot-2.1.7/lib/dovecot/libdovecot-storage.so.0(mdbox_storage_sync_init+0x7e)
[0x7faa3be631be] ->
/opt/dovecot-2.1.7/lib/dovecot/libdovecot-storage.so.0(mailbox_sync_init+0x31)
[0x7faa3bea2871] ->
/opt/dovecot-2.1.7/lib/dovecot/libdovecot-storage.so.0(mailbox_sync+0x27)
[0x7faa3bea2997] ->
/opt/dovecot-2.1.7/lib/dovecot/libdovecot-storage.so.0(index_storage_get_status+0x8a)
[0x7faa3bec47da] -> /opt/dovecot/lib/dovecot/lib20_fts_plugin.so(+0xc002)
[0x7faa3a775002] -> /opt/dovecot/bin/dsync() [0x42bf9a] ->
/opt/dovecot/bin/dsync(dsync_worker_mailbox_iter_next+0x29) [0x428eb9] ->
/opt/dovecot/bin/dsync() [0x423bfe] ->
/opt/dovecot/bin/dsync(dsync_brain_sync+0x832) [0x4233a2] ->
/opt/dovecot/bin/dsync(dsync_brain_sync_all+0x18) [0x423ee8] ->
/opt/dovecot/bin/dsync() [0x420f36] -> /opt/dovecot/bin/dsync() [0x4215b2]
-> /opt/dovecot/bin/dsync() [0x40e798] -> /opt/dovecot/bin/dsync()
[0x40f1ea]