why does setup keep trying to install non-required packages?

[Andrew Schulman]

Fairly often when I run setup just for updates, it selects new packages 
for
installation that I haven't selected and that aren't required by any of 
my
other packages.

Right now setup wants to install the login package.  I didn't select 
it,
and if I unselect it the installation continues without any problem.  
It
happened in setup-x86, and now setup-x86_64 wants to do it too.  I try 
to
keep my installation slim, so I don't want setup to add new packages 
that
aren't required and that I didn't select.

Has anyone else observed this?  Know the reason?  Are they new 
packages,
and setup assumes I want all new packages?

Thanks,
Andrew.