$ git clone -n https://src.fedoraproject.org/rpms/rust-num-rational.git /var/lib/mock/f45-build-43456-803/root/chroot_tmpdir/scmroot/rust-num-rational
Cloning into '/var/lib/mock/f45-build-43456-803/root/chroot_tmpdir/scmroot/rust-num-rational'...
$ git fetch origin 88df5c83749359df37f9d3934e5d38ac65687db0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-num-rational
 * [new ref]         88df5c83749359df37f9d3934e5d38ac65687db0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 88df5c8 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild