$ git clone -n https://src.fedoraproject.org/rpms/librepo.git /var/lib/mock/f45-build-43640-804/root/chroot_tmpdir/scmroot/librepo
Cloning into '/var/lib/mock/f45-build-43640-804/root/chroot_tmpdir/scmroot/librepo'...
$ git fetch origin 1676771ffdb6609eb0e954733f8fee3bd695c3ab:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/librepo
 * [new ref]         1676771ffdb6609eb0e954733f8fee3bd695c3ab -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1676771 Rebuilt for libxml2-2.15.4 (again)