$ git clone -n https://src.fedoraproject.org/rpms/rust-gix-submodule.git /var/lib/mock/f40-build-2712341-71993/root/chroot_tmpdir/scmroot/rust-gix-submodule
Cloning into '/var/lib/mock/f40-build-2712341-71993/root/chroot_tmpdir/scmroot/rust-gix-submodule'...
$ git fetch origin 9d50c10aacce9138c86e4e718ecd226e3ab0ead0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-gix-submodule
 * [new ref]         9d50c10aacce9138c86e4e718ecd226e3ab0ead0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9d50c10 Update to version 0.10.0 (rhbz#2253283)