If the Data sources config is incorrect so that the <driver> element does not match an existing driver, the error message is cryptic.

JBAS014775: New missing/unsatisfied dependencies:
service jboss.jdbc-driver.db2xa (missing) dependents: [service jboss.data-source.java:jboss/datasources/myDS]

I would expect a log message at ERROR level, there is no error message while other data sources are loaded.

Missing dependencies is printed on a line with no error level and the text of the message does not relate to the XML.

I would expect the error message to indicate something about where to fix the error.

e.g an XPath

subsystem[xmlns="urn:jboss:domain:datasources:1.0"]/datasources/datasource/driver.

or some text that indicates the <driver> element is the problem.