PDF not created; "[no paths to render]"

[anthrolisp]

I'm very interested in this for my pollen workflow, but the command does not seem to render the PDF and outputs with an error. See below:

$:~/Documents/associate$ raco pollen render examples/down-the-foxhole.pdf
pollen: rendering examples/down-the-foxhole.pdf
pollen: [no paths to render]
$:~/Documents/associate$ raco pollen render examples/gale-cup.pdf
pollen: rendering examples/gale-cup.pdf
pollen: [no paths to render]

Many thanks in advance!