Hello, this seems to be critical bug in [BaseX7.8.2]. The following code
let $a := <element></element>
for $i in (1 to 5)
return copy $b := $a modify (
insert node attribute id { generate-id() } into $b
)
return $b
will return elements with the same IDs, i.e.:
<element id="id31442"/>
<element id="id31442"/>
<element id="id31442"/>
<element id="id31442"/>
<element id="id31442"/>