I have a securefs volume created with an older version of securefs and it uses the old ".securefs.json" config file.
When this volume is mounted, the ".securefs.lock" file is created normally but it is not deleted when unmounting.
Logs also has a mistleading entry since it thinks the previous instance crashed
securefs::full_format::RepoLocker::open_lock_stream_checked():698] Lock file $PATH/.securefs.lock exists but the process holding it has exited. The previous securefs probably exited abnormally.