Also sprach Guenter Milde:
The error message is clear: it says "... requires XeTeX".
Then we can check for this message. Do you have TeXLive 2009, Günter? Can you setup a minimal example file?
We had already the discussion with testing the fontspec date. IMO, this should be done using Python code.
Yes, I still have this message marked in my inbox. But you didn't yet propose a working python code, did you?
OTOH JMarc's idea of using a test file strikes me not too bad. Jürgen
