[xsl] Can't get expath-file functions to work in Saxon 9.5 PE

[Martin Holmes <mholmes@xxxxxxx>]

Hi there,

I'm using Saxon 9.5.1.3 PE in Oxygen 15.2 with XSLT 2.0. I'm trying to 
use the expath-file functions, which the documentation says are 
available. This is a simple version of what I'm trying:


 ...xmlns:expath-file="http://expath.org/ns/file";...

 <xsl:variable name="tempDir" as="xs:string" 
select="'/home/mholmes/temptest'"/>

 <xsl:sequence select="expath-file:create-dir($tempDir)"/>

 [... do stuff ...]

 <xsl:sequence select="expath-file:delete-dir($tempDir, true())"/>

In both cases, I get errors like this:

Severity: fatal
Description: XPST0017 XPath syntax error at char 0 on line 75 in 
{expath-file:delete-dir($tempDi...}: Cannot find a matching 2-argument 
function named {http://expath.org/ns/file}delete-dir()
Start location: 75:86
URL: http://www.w3.org/TR/xpath20/#ERRXPST0017

My Oxygen preferences are set to "Allow calls on extension functions". 
Is there something special I need to configure in order to make 
expath-file functions work? I've tried prefixing the path with "file:/", 
"file:///" and everything else I can think of.

Cheers,
Martin