as of this morning US time we have changed the way rawhide buildroots are
created in koji. rawhide is now using dnf to install the packages into the
buildroot. this means that in f24 and on dnf will be used to create the
buildroot. as well as manage the updates on your system.
We will not be making the same change to f22 or f23 in koji, yum will
continue to create the buildroot there. please report to Release Engineering
 any issue you encounter as a result of this change.
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 file a ticket in trac https://fedorahosted.org/rel-eng/
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