Pure x86_64? Why are i586 packages pulled as dependences?

[Joshua C.]

I build a x86_64 live cd and speficied only x86_64 repos. At the end I
saw some i586 and one i686 packages. I do customized the kickfiles and
added some -devel packages but I thought only x86_64 packages would be
pulled.

Then when trying to update some x86_64 packages on the livecd (running
it as livecd) I saw that many i586 are pulled as dependences. At the
end there were lots of duplets.

How to make a "pure" x86_64 livecd?