$ git clone -n https://src.fedoraproject.org/rpms/rust-ar_archive_writer.git /var/lib/mock/f45-build-40103-768/root/chroot_tmpdir/scmroot/rust-ar_archive_writer
Cloning into '/var/lib/mock/f45-build-40103-768/root/chroot_tmpdir/scmroot/rust-ar_archive_writer'...
$ git fetch origin 7db334517dcc8c578792cddb9e772140cd4184c5:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-ar_archive_writer
 * [new ref]         7db334517dcc8c578792cddb9e772140cd4184c5 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 7db3345 Initial import (#2512915)