$ git clone -n https://src.fedoraproject.org/rpms/rust-gix-index.git /var/lib/mock/f38-build-side-43-rust-devel-1422008-31465/root/chroot_tmpdir/scmroot/rust-gix-index
Cloning into '/var/lib/mock/f38-build-side-43-rust-devel-1422008-31465/root/chroot_tmpdir/scmroot/rust-gix-index'...
$ git fetch origin b0029470afce7a05fc5279ac448192c6f834b968:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-gix-index
 * [new ref]         b0029470afce7a05fc5279ac448192c6f834b968 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b002947 Update to version 0.26.0