$ git clone -n https://src.fedoraproject.org/rpms/rust-cfb-mode.git /var/lib/mock/f45-build-40726-775/root/chroot_tmpdir/scmroot/rust-cfb-mode
Cloning into '/var/lib/mock/f45-build-40726-775/root/chroot_tmpdir/scmroot/rust-cfb-mode'...
$ git fetch origin ffc2837da70a5280d0f5bb569d611b09d2e6e91f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-cfb-mode
 * [new ref]         ffc2837da70a5280d0f5bb569d611b09d2e6e91f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ffc2837 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild