$ git clone -n https://src.fedoraproject.org/rpms/rust-tokei.git /var/lib/mock/f40-build-780248-130831/root/chroot_tmpdir/scmroot/rust-tokei
Cloning into '/var/lib/mock/f40-build-780248-130831/root/chroot_tmpdir/scmroot/rust-tokei'...
$ git fetch origin 4d003bae7cfcf5e199f4968c39c98b9277f3f5eb:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-tokei
 * [new ref]         4d003bae7cfcf5e199f4968c39c98b9277f3f5eb -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4d003ba Bump git2 dev-dependency from 0.13 to 0.18