login package source?

[glhenni@cs.sandia.gov (Gary L. Hennigan)]

I'm having problems with the newgrp command. Whenever I try to change
my primary group with it, as a user, I get:

% newgrp - audio
getgroups: Invalid argument

I suspect something in my environment is causing the problem, since it 
seems to work ok for other users, and root. I've had trouble like this 
before and I've resorted to getting the source, compiling it for debug 
and chasing down the trouble. Problem is I can't find the source for
the login package. The package is part of "base" but there doesn't
seem to be a source package for it. Anyone know where I can pick it
up?

Thanks,
Gary