Dear Herbert,
> I'm getting the error
> kpathsea: Invalid fontname `Asana Math/ICU', contains ' '
> when I use
> \usepackage{unicode-math}
> \setmathfont{Asana Math}
> and typeset using xelatex.
Here it works fine. Maybe Asana-Math.otf is not cached.
Can you see an output of
fc-list | grep 'Asana Math' ?
Best,
Akira