$ git clone -n https://src.fedoraproject.org/rpms/rust-atomic-traits.git /var/lib/mock/f41-build-side-1-2934415-35233/root/chroot_tmpdir/scmroot/rust-atomic-traits
Cloning into '/var/lib/mock/f41-build-side-1-2934415-35233/root/chroot_tmpdir/scmroot/rust-atomic-traits'...
$ git fetch origin c619a719b903c3e0bde86b57d2bfa9d88e37f959:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-atomic-traits
 * [new ref]         c619a719b903c3e0bde86b57d2bfa9d88e37f959 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c619a71 unused leaf package for more than two release cycles