$ git clone -n https://src.fedoraproject.org/rpms/rust-uu_join.git /var/lib/mock/f40-build-774051-127571/root/chroot_tmpdir/scmroot/rust-uu_join
Cloning into '/var/lib/mock/f40-build-774051-127571/root/chroot_tmpdir/scmroot/rust-uu_join'...
$ git fetch origin 8ef073012b1bd32a062a0bfc4175f37e531bf904:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-uu_join
 * [new ref]         8ef073012b1bd32a062a0bfc4175f37e531bf904 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8ef0730 Initial package (rhbz#2258135)