Hi,

I'm writing a package definition for
[passff-host](https://github.com/passff/passff-host) which requires a
file to reference another file with an absolute path (passff.json must
reference passff.py). How can I get the resulting store path to patch it
to the file? I would assume I have to do something with gexps but
couldn't figure it out by reading the documentation.

- Saku Laesvuori