@Tim Edwards do not use '.' in search paths, use instead

[pwd]

or

$env(HOME)

. In Xschem '.' refers to the directory of the currently loaded schematic, not the current working directory where the tool has been started from. This '.' interpretation has some use cases (a schematic referencing other symbols with just their name will find them in the directory containing the current schematic) but has also some disadvantages. My suggestion is to avoid using it.

That was my solution. But it's useful to know the reason my first try didn't work. Thanks!