Hi Brett,
The issue is located in the org.hibernate.spatial.Circle class of Hibernate Spatial, and http://www.hibernatespatial.org/documentation/01-download/03-repo/ says that hibernate spatial is being integrated in hibernate (also see HHH-6509). That is why I thought this was the right JIRA project.
(I also tried https://github.com/maesenka/hibernate-core/blob/HHH-6509%2Bmetamodel/hibernate-spatial/src/main/java/org/hibernate/spatial/jts/Circle.java, which gave the same error.)
Is it really the wrong project?

Kind regards,

Erwin