$ git clone -n https://src.fedoraproject.org/rpms/rust-cxx-gen.git /var/lib/mock/f40-build-2091944-50254/root/chroot_tmpdir/scmroot/rust-cxx-gen
Cloning into '/var/lib/mock/f40-build-2091944-50254/root/chroot_tmpdir/scmroot/rust-cxx-gen'...
$ git fetch origin fda355b018598359d118538d9a6fea503e847806:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-cxx-gen
 * [new ref]         fda355b018598359d118538d9a6fea503e847806 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at fda355b update to version 0.7.110 (rhbz#2246686)