When we build python-copr with %generate_buildrequires section, there are four loops:

1. reports missing wheel package, so mock installs that
2. reports missing marshmallow, requests-toolbelt, ... etc., so mock installs that
3. reports that nothing is missed (based on log), but it still probably returns status 11 (weird), I'm not sure what is going on, so mock installs nothing (dnf says "Nothing to do.").
4. reports the same - that nothing is missing, and now finally mock continues with the %build section.

I'm not yet sure who is responsible for the additional loop, so filling it here for now.