$ git clone -n https://src.fedoraproject.org/rpms/rust-rand_chacha0.3.git /var/lib/mock/f45-build-44236-811/root/chroot_tmpdir/scmroot/rust-rand_chacha0.3
Cloning into '/var/lib/mock/f45-build-44236-811/root/chroot_tmpdir/scmroot/rust-rand_chacha0.3'...
$ git fetch origin 87047c1c8fbac70ca86d48027d86813c4aa66d74:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-rand_chacha0.3
 * [new ref]         87047c1c8fbac70ca86d48027d86813c4aa66d74 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 87047c1 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild