$ git clone -n https://src.fedoraproject.org/rpms/python-xnat.git /var/lib/mock/f42-build-side-1-3500293-45970/root/chroot_tmpdir/scmroot/python-xnat
Cloning into '/var/lib/mock/f42-build-side-1-3500293-45970/root/chroot_tmpdir/scmroot/python-xnat'...
$ git fetch origin 9f68f3621787de00c4d4ba4cca66f3297b4bac4e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/python-xnat
 * [new ref]         9f68f3621787de00c4d4ba4cca66f3297b4bac4e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9f68f36 Drop patch (merged upstream)