See attachment for a minimal maven project that reproduces the error.

Note that the maven build won’t fail, since the metamodel generator will run with default settings. However you will see the warning in the maven log:

{noformat}
[INFO] diagnostic: Note: Hibernate JPA 2 Static-Metamodel Generator 5.4.10.Final [WARNING] diagnostic: warning: Unable to parse persistence.xml: Unable to perform unmarshalling at line number 0 and column 0. Message: null
{noformat}