Saxon

The following XQuery code incorrectly tries to use an xs:string as an xs:token and Saxon raises an error but somehow the Java net.sf.saxon.Query command line tool doesn't just report it but generates a stack trace.

let $s := '   abc   ',
    $t := $s cast as xs:token,
    $t2 as xs:token := $s
return ($s, $t, $t2) ! ('|' || . || '|')

Stack trace:

 java -cp 'C:\Program Files\Saxonica\SaxonHE12-5J\saxon-he-12.5.jar' net.sf.saxon.Query .\token-test2.xq
<?xml version="1.0" encoding="UTF-8"?>|   abc   | |abc|net.sf.saxon.trans.UncheckedXPathException: The required item type of the value of variable $t2 is xs:token; the supplied value "   abc   " does not match. The supplied value is of type xs:string
        at net.sf.saxon.expr.ItemChecker.lambda$checkSequence$0(ItemChecker.java:252)
        at net.sf.saxon.expr.ItemCheckingIterator.next(ItemCheckingIterator.java:63)
        at net.sf.saxon.expr.instruct.AbstractBlockIterator.next(AbstractBlockIterator.java:71)
        at net.sf.saxon.om.FocusTrackingIterator.next(FocusTrackingIterator.java:72)
        at net.sf.saxon.expr.instruct.ForEach$ForEachElaborator.lambda$elaborateForPush$5(ForEach.java:811)
        at net.sf.saxon.query.XQueryExpression.processQuery(XQueryExpression.java:499)
        at net.sf.saxon.query.XQueryExpression.run(XQueryExpression.java:473)
        at net.sf.saxon.s9api.XQueryEvaluator.run(XQueryEvaluator.java:466)
        at net.sf.saxon.Query.runQuery(Query.java:1006)
        at net.sf.saxon.Query.doQuery(Query.java:457)
        at net.sf.saxon.Query.doQuery(Query.java:516)
        at net.sf.saxon.Query.main(Query.java:107)
Caused by: net.sf.saxon.trans.XPathException: The required item type of the value of variable $t2 is xs:token; the supplied value "   abc   " does not match. The supplied value is of type xs:string
        at net.sf.saxon.expr.ItemChecker.lambda$checkSequence$0(ItemChecker.java:248)
        ... 11 more
Fatal error during query: net.sf.saxon.trans.UncheckedXPathException: The required item type of the value of variable $t2 is xs:token; the supplied value "   abc   " does not match. The supplied value is of type xs:string

SaxonCS (tested with 12.5) also gives a similar stack trace:

 & 'C:\Program Files\Saxonica\SaxonCS-12.5\SaxonCS.exe' query .\token-test2.xq
<?xml version="1.0" encoding="UTF-8"?>|   abc   | |abc|Saxon.Hej.trans.UncheckedXPathException
 ---> Saxon.Hej.trans.XPathException: The required item type of the value of variable $t2 is xs:token; the supplied value "   abc   " does not match.
   --- End of inner exception stack trace ---
   at Saxon.Hej.expr.ItemChecker.<>c__DisplayClass13_0.<checkSequence>b__0(Item item)
   at Saxon.Hej.expr.ItemCheckingIterator.next()
   at Saxon.Hej.expr.instruct.AbstractBlockIterator.next()
   at Saxon.Hej.om.FocusTrackingIterator.next()
   at Saxon.Hej.expr.instruct.ForEach.ForEachElaborator.<>c__DisplayClass2_0.<elaborateForPush>b__1(Outputter out, XPathContext context)
   at Saxon.Eej.ee.optim.XQueryExpressionEE.processQuery(Outputter dest, XPathContext context)
   at Saxon.Hej.query.XQueryExpression.run(DynamicQueryContext env, Result result, Properties outputProperties)
   at Saxon.Hej.s9api.XQueryEvaluator.run(Destination destination)
   at Saxon.Hej.Query.runQuery(XQueryExecutable exp, XQueryEvaluator evaluator, Source input, Destination destination)
   at Saxon.Hej.Query.doQuery(String[] args)
Fatal error during query: UncheckedXPathException:
Exiting with code 2

I