How to tell what repo/mirror yum is using

["Andy Burns" <fedora lists burns me uk>]

I have a local mirror of development but not extras-development, that
I periodically refresh manually, so i can reproduce identical installs
and only get bang up-to-date when I'm ready.

Sometimes I think yum is using a wrong mirror, in reality when I check
it usually turns out yum *is* using my mirror, but it seems surprising
to me that none of the -d levels actually tell you the actual URL it
is using, or have I missed something?