OnlyClassesCanHaveDeclaredButUndefinedMembers

Does this message have an explanation? This is normally the same as explain.nonEmpty but can be overridden if we need a way to return true without actually calling the explain method.

A message is non-sensical if it contains references to tags. Such tags are inserted by the error diagnostic framework if a message contains references to internally generated error types. Normally we want to suppress error messages referring to types like this because they look weird and are normally follow-up errors to something that was diagnosed before.

The implicit Context in messages is a large thing that we don't want persisted. This method gets around that by duplicating the message, forcing its msg and explanation vals and dropping the implicit context that was captured in the original message.

The message with potential embedded tags

The explanation to report. tags are filtered out

The message to report. tags are filtered out