Hi John,
that's correct - attributes cannot be serialized. It's not the fault of BaseX; the reason are intricacies of the serialization model [1]. (The attributes would become attributes of a document node, which is not possible.)
Perhaps you can get avoid the problem by attaching to your query expression which yields the attributes /string(), like //a/@b/string()?
Kind regards,
Hans-Jürgen
[1] http://www.w3.org/TR/xslt-xquery-serialization/
John Best <johnbest5673@gmail.com> schrieb am 9:09 Mittwoch, 2.April 2014: