Creating a simple `RESOURCE_LOCAL` persistence unit where connection properties `javax.persistence.jdbc.driver`, `javax.persistence.jdbc.url`, `javax.persistence.jdbc.user` and `javax.persistence.jdbc.password` are specified in source code and passed to `EntityManagerFactory.createEntityManager(Map)` can fail with
which isn't overly helpful because a connection is supplied - something else is meant here, but that something should be explained to the user. In case this feedback can't be improved, suggestions of the cause have to be supplied in the exception message, i.e. `The application must supply JDBC connections (did you forget to specify xyz at abc (was empty))`.
EclipseLink fails with
Please note that this is not a support request for workaround and possible causes of the issue and I'm not eager to get this fixed for myself, but rather for everyone.
An example can be found at https://github.com/krichter722/hibernate-supply-connections-feedback.