= phenomenon =
Yum fails to connect to Fedora copr repositories because curl complains about unrecognised certificate.

= reason =
The repo file provided by the project page uses https urls. Fedora copr however, uses a self-signed (by Red Hat) security certificate. Of course this means curl fails to identify the certificate as valid.

= recommendation =
Use a recognised CA signed security certificate for Fedora copr.
Of course the less secure alternative would be to use plain http urls in the generated repo files.