$ git clone -n https://src.fedoraproject.org/rpms/rust-itertools-num.git /var/lib/mock/f41-build-side-1-3098682-39333/root/chroot_tmpdir/scmroot/rust-itertools-num
Cloning into '/var/lib/mock/f41-build-side-1-3098682-39333/root/chroot_tmpdir/scmroot/rust-itertools-num'...
$ git fetch origin 17b25f312d7c9e8c0090b1ebe37df6334611d473:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-itertools-num
 * [new ref]         17b25f312d7c9e8c0090b1ebe37df6334611d473 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 17b25f3 no longer needed