I just deployed new version of Copr at:
It have only one feature: you can now build in epel-7-x86_64!
To be precise - the name "epel" is little bit misleading, because it is
right now based on RHEL 7 Beta and does not include EPEL repo, because
it does not exists yet.
But one day I will flip to Centos 7 and EPEL 7 and I do not want you to
change chroots and configs, while I want to provide you the option of
hacking your packages on top not-yet-finished RHEL 7.