$ git clone -n https://src.fedoraproject.org/rpms/qpdfview.git /var/lib/mock/f42-build-864524-172396/root/chroot_tmpdir/scmroot/qpdfview
Cloning into '/var/lib/mock/f42-build-864524-172396/root/chroot_tmpdir/scmroot/qpdfview'...
$ git fetch origin fdbcd09a37e7661a4bab67515d6ecb421b98ba9a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/qpdfview
 * [new ref]         fdbcd09a37e7661a4bab67515d6ecb421b98ba9a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at fdbcd09 Rebuild (mupdf)