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]