The manpage polygen-data(6) says:
SYNOPSIS
polygen grammar
[...]
English grammars
designpatterns.grm
Object-oriented Design Patterns
genius.grm
The computer genius
[...]
Thus, I expected that
polygen genius.grm
would work, but it doesn't:
ajk@kukkaseppele:~$ polygen genius.grm
error: cannot parse from file "genius.grm: No such file or directory"
Specifying the full path does work, but if the above is not intended to
work, then the man page should be made clearer (and preferably tell us
where the grammar files are; I had to dpkg -L to find out).