$ git clone -n https://src.fedoraproject.org/rpms/arianna.git /var/lib/mock/f38-build-side-42-init-devel-1356055-30698/root/chroot_tmpdir/scmroot/arianna
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-1356055-30698/root/chroot_tmpdir/scmroot/arianna'...
$ git fetch origin b0450ccd4d417dd2fbf326b3c5a206b96da9821c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/arianna
 * [new ref]         b0450ccd4d417dd2fbf326b3c5a206b96da9821c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b0450cc Update to 1.1.0