$ git clone -n https://src.fedoraproject.org/rpms/rust-once_cell.git /var/lib/mock/f45-build-43525-803/root/chroot_tmpdir/scmroot/rust-once_cell
Cloning into '/var/lib/mock/f45-build-43525-803/root/chroot_tmpdir/scmroot/rust-once_cell'...
$ git fetch origin 945e3936dfe04d71ff347ed08cd68f8178a829c6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-once_cell
 * [new ref]         945e3936dfe04d71ff347ed08cd68f8178a829c6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 945e393 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild