indexer-worker assert in v2.2.28 (fts-lucene)

[Daniel J. Luke]

I upgraded to 2.2.28 and started seeing this logged:

indexer-worker(dluke): Panic: file mailbox-list.c: line 1158 (mailbox_list_try_mkdir_root): assertion failed: (strncmp(root_dir, path, strlen(root_dir)) == 0)
indexer-worker(dluke): Error: Raw backtrace: 
2   libdovecot.0.dylib                  0x000000010ec63d24 default_fatal_finish + 36 
-> 3   libdovecot.0.dylib                  0x000000010ec64b5b i_internal_fatal_handler + 43 
-> 4   libdovecot.0.dylib                  0x000000010ec64039 i_panic + 169 
-> 5   libdovecot-storage.0.dylib          0x000000010eac0950 mailbox_list_try_mkdir_root + 1248 
-> 6   libdovecot-storage.0.dylib          0x000000010eac0a39 mailbox_list_mkdir_root + 25 
-> 7   lib21_fts_lucene_plugin.so          0x0000000110adc949 fts_backend_lucene_update_set_build_key + 73 
-> 8   lib20_fts_plugin.so                 0x000000010ee736cf fts_backend_update_set_build_key + 79 
-> 9   lib20_fts_plugin.so                 0x000000010ee74317 fts_build_mail + 599 
-> 10  lib20_fts_plugin.so                 0x000000010ee7981a fts_mail_precache + 794 
-> 11  libdovecot-storage.0.dylib          0x000000010eaa71e9 mail_precache + 25 
-> 12  indexer-worker                      0x000000010ea9e503 master_connection_input + 1523
-> 13  libdovecot.0.dylib                  0x000000010ec78b89 io_loop_call_io + 89 
-> 14  libdovecot.0.dylib                  0x000000010ec7a96d io_loop_handler_run_internal + 269 
-> 15  libdovecot.0.dylib                  0x000000010ec7907f io_loop_handler_run + 303 
-> 16  libdovecot.0.dylib                  0x000000010ec78e58 io_loop_run + 88 
-> 17  libdovecot.0.dylib                  0x000000010ec03458 master_service_run + 24 
-> 18  indexer-worker                      0x000000010ea9ddb4 main + 340 
-> 19  libdyld.dylib                       0x00007fffba7df255 start + 1

Anyone else? 
-- 
Daniel J. Luke