$ git clone -n https://src.fedoraproject.org/rpms/rust-tokio-udp.git /var/lib/mock/f41-build-side-1-3129205-39576/root/chroot_tmpdir/scmroot/rust-tokio-udp
Cloning into '/var/lib/mock/f41-build-side-1-3129205-39576/root/chroot_tmpdir/scmroot/rust-tokio-udp'...
$ git fetch origin 822d1e8c4b52db4e28b690b7e890aa436cd67406:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-tokio-udp
 * [new ref]         822d1e8c4b52db4e28b690b7e890aa436cd67406 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 822d1e8 no longer needed