Why do I see unknown source in stack traces when I have sources downloaded?

Hi All,

I was wanting to dig into the details of an Exception I was getting running unit tests but the stack trace parts for HSQLDB show as Unknown Source. I am using Maven and I have sources and documents downloaded and I can see them defined correctly in the IDE.

Any ideas why I would still see Unknown Source?

TIA

Caused by: org.hsqldb.HsqlException: incompatible data type in operation
at org.hsqldb.error.Error.error(Unknown Source)
at org.hsqldb.error.Error.error(Unknown Source)
at org.hsqldb.NumberSequence.setDefaults(Unknown Source)
at org.hsqldb.NumberSequence.<init>(Unknown Source)
at org.hsqldb.ParserTable.readColumnDefinitionOrNull(Unknown Source)
at org.hsqldb.ParserTable.readTableContentsSource(Unknown Source)
at org.hsqldb.ParserTable.compileCreateTableBody(Unknown Source)
at org.hsqldb.ParserTable.compileCreateTable(Unknown Source)
at org.hsqldb.ParserDDL.compileCreate(Unknown Source)
at org.hsqldb.ParserCommand.compilePart(Unknown Source)
at org.hsqldb.ParserCommand.compileStatements(Unknown Source)
at org.hsqldb.Session.executeDirectStatement(Unknown Source)
at org.hsqldb.Session.execute(Unknown Source)