That command works, but it takes a VERY LONG time to complete (maybe 5mins).
dnf -y repository-packages MYREPO upgrade
Earlier version of DNF (maybe few weeks ago), throw these messages while doing upgrade:
Package SOMEPACKAGE1 not installed, cannot update it
Package SOMEPACKAGE2 not installed, cannot update it
Package SOMEPACKAGE3 not installed, cannot update it
Package SOMEPACKAGE4 not installed, cannot update it
I assume that the problem could be in the fact that DNF is trying to update ALL packages from my custom repository MYREPO, but on my PC, I use only few of those packages (have installed) just a few packages.