Unable to auth with userspace module

[Ludvig Ericson]

Okay, it's me again.

I don't know what was wrong with it, but now I can at least
authenticate with an ad-hoc self-written C program, but there's a
follow-up on that, I can't do pam_acct_mgmt() on any user; following
error occurs:
pam_acct_mgmt() error 9: Authentication service cannot retrieve
authentication info
Does this just mean that my backend doesn't support what
pam_acct_mgmt() wants to do?