$ git clone -n https://src.fedoraproject.org/rpms/rust-scratch.git /var/lib/mock/f45-build-44714-816/root/chroot_tmpdir/scmroot/rust-scratch
Cloning into '/var/lib/mock/f45-build-44714-816/root/chroot_tmpdir/scmroot/rust-scratch'...
$ git fetch origin 1be8e5d1f3ba1f4af3dd39c1afe6ab5bc1e4137e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-scratch
 * [new ref]         1be8e5d1f3ba1f4af3dd39c1afe6ab5bc1e4137e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1be8e5d Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild