default installonlypkgs includes "installonlypkg(kernel)", but packages like kernel-PAE, kernel-lpae and others are still not allowed to be installed multiple time.
*** Bug 1382246 has been marked as a duplicate of this bug. ***
Fixed by PR: https://github.com/rpm-software-management/dnf/pull/631
*** Bug 1199715 has been marked as a duplicate of this bug. ***
wondering if we have this bug in libdnf..