$ git clone -n https://src.fedoraproject.org/rpms/qpdfview.git /var/lib/mock/f45-build-33965-675/root/chroot_tmpdir/scmroot/qpdfview
Cloning into '/var/lib/mock/f45-build-33965-675/root/chroot_tmpdir/scmroot/qpdfview'...
$ git fetch origin b95f375486f5512f29741b1184fc29f9843894a6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/qpdfview
 * [new ref]         b95f375486f5512f29741b1184fc29f9843894a6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b95f375 Rebuild (mupdf)