$ git clone -n https://src.fedoraproject.org/rpms/kf5-purpose.git /var/lib/mock/f40-build-787996-134983/root/chroot_tmpdir/scmroot/kf5-purpose
Cloning into '/var/lib/mock/f40-build-787996-134983/root/chroot_tmpdir/scmroot/kf5-purpose'...
$ git fetch origin 9c778c096545fa37eaf30ed465db01af9807cdf5:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/kf5-purpose
 * [new ref]         9c778c096545fa37eaf30ed465db01af9807cdf5 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9c778c0 5.115.0