$ git clone -n https://src.fedoraproject.org/rpms/rust-rfc6979.git /var/lib/mock/f38-build-side-43-rust-devel-1413799-31445/root/chroot_tmpdir/scmroot/rust-rfc6979
Cloning into '/var/lib/mock/f38-build-side-43-rust-devel-1413799-31445/root/chroot_tmpdir/scmroot/rust-rfc6979'...
$ git fetch origin a4f8c40377a1c332f0ffaeaf99385f8f267ba11c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-rfc6979
 * [new ref]         a4f8c40377a1c332f0ffaeaf99385f8f267ba11c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a4f8c40 Adapt package summary to better reflect the project description