$ git clone -n https://src.fedoraproject.org/rpms/kf6-purpose.git /var/lib/mock/f41-build-838847-159865/root/chroot_tmpdir/scmroot/kf6-purpose
Cloning into '/var/lib/mock/f41-build-838847-159865/root/chroot_tmpdir/scmroot/kf6-purpose'...
$ git fetch origin e31cc20d63b706c0421edc44e85a69febf54dcac:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/kf6-purpose
 * [new ref]         e31cc20d63b706c0421edc44e85a69febf54dcac -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e31cc20 6.5.0