$ git clone -n https://src.fedoraproject.org/rpms/light.git /var/lib/mock/f45-build-17344-498/root/chroot_tmpdir/scmroot/light
Cloning into '/var/lib/mock/f45-build-17344-498/root/chroot_tmpdir/scmroot/light'...
$ git fetch origin 2fdd77568204c1b3da4d8578ab411d80f6c574b8:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/light
 * [new ref]         2fdd77568204c1b3da4d8578ab411d80f6c574b8 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2fdd775 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild