$ git clone -n https://src.fedoraproject.org/rpms/rust-krata-tokio-tar.git /var/lib/mock/f42-build-side-1-3504292-45983/root/chroot_tmpdir/scmroot/rust-krata-tokio-tar
Cloning into '/var/lib/mock/f42-build-side-1-3504292-45983/root/chroot_tmpdir/scmroot/rust-krata-tokio-tar'...
$ git fetch origin 66cc71525395ee24550626aca79d88b2e1d7cba6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-krata-tokio-tar
 * [new ref]         66cc71525395ee24550626aca79d88b2e1d7cba6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 66cc715 no longer needed