$ git clone -n https://src.fedoraproject.org/rpms/arc-theme.git /var/lib/mock/f41-build-side-1-2631836-25742/root/chroot_tmpdir/scmroot/arc-theme
Cloning into '/var/lib/mock/f41-build-side-1-2631836-25742/root/chroot_tmpdir/scmroot/arc-theme'...
$ git fetch origin 15fb4a3fedb937696750955904f251107e0db55d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/arc-theme
 * [new ref]         15fb4a3fedb937696750955904f251107e0db55d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 15fb4a3 convert GPLv3+ license to SPDX