$ git clone -n https://src.fedoraproject.org/rpms/rust-is-docker.git /var/lib/mock/f45-build-42668-795/root/chroot_tmpdir/scmroot/rust-is-docker
Cloning into '/var/lib/mock/f45-build-42668-795/root/chroot_tmpdir/scmroot/rust-is-docker'...
$ git fetch origin 4785a36eb093af83fb7c39a6bf5379be3756ef36:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-is-docker
 * [new ref]         4785a36eb093af83fb7c39a6bf5379be3756ef36 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4785a36 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild