fedora-packager-setup asks for the FAS username like this:

{{{
Setting up Fedora packager environment
You need a client certificate from the Fedora Account System, lets get one now
FAS Username: ciupicri
FAS Password:
}}}

In order to reduce typing it should perhaps default to the ''Unix'' username of the person running the program. The os.getlogin() Python function should do it.