Deadlock failure that does not occur elsewhere

MariaDB gets the following deadlock error:

localhost-dir: sql_create.c:837-5 Fill File table Query failed: INSERT INTO File
(FileIndex, JobId, PathId, FilenameId, LStat, MD5, DeltaSeq) SELECT
batch.FileIndex, batch.JobId, Path.PathId, Filename.FilenameId,batch.LStat,
batch.MD5, batch.DeltaSeq FROM batch JOIN Path ON (batch.Path = Path.Path) JOIN
Filename ON (batch.Name = Filename.Name): ERR=Deadlock found when trying to get
lock;

When running the Bacula 9.0.1 regression script named: three-pool-virtual-test
This does not occur on any version of MySQL, nor the Ubuntu version 10.0 of MariaDB. The code has been stable for many years.

I am running all instances of MariaDB and MySQL out of the box. I have changed no parameters.

This appears to be a false deadlock detection. Note, it is 100% reproducible.