Thank God for yum-deprecated :-)

[Tom Horsley]

I see that dnf, in its infinite wisdom, has classified
ignoring packages it can't find as a bug, therefore
if you say

dnf install `cat f22-missing.txt`

to install as much stuff as possible in your new
f22 as you used to have in f20, it will find the
very first missing rpm (and ONLY the first), tell
you it isn't in the repos, and quit.

See: https://bugzilla.redhat.com/show_bug.cgi?id=1224485

So you delete it from the list and try again, which
let's you find the 2nd one, repeat for several weeks,
or discover there is a yum-deprecated out there and
run:

yum-deprecated install `cat f22-missing.txt`

which will actually install everything it can and
ignore the ones it can't find, thus saving you
many hours of fixing the list or installing
one package at a time with dnf.