$ git clone -n https://src.fedoraproject.org/rpms/rust-bb8.git /var/lib/mock/f45-build-40478-772/root/chroot_tmpdir/scmroot/rust-bb8
Cloning into '/var/lib/mock/f45-build-40478-772/root/chroot_tmpdir/scmroot/rust-bb8'...
$ git fetch origin f4251ee1938f8376696f4006e6d6ec199cb64ba9:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-bb8
 * [new ref]         f4251ee1938f8376696f4006e6d6ec199cb64ba9 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f4251ee Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild