$ git clone -n https://src.fedoraproject.org/rpms/plasma-desktop.git /var/lib/mock/f40-build-803669-144324/root/chroot_tmpdir/scmroot/plasma-desktop
Cloning into '/var/lib/mock/f40-build-803669-144324/root/chroot_tmpdir/scmroot/plasma-desktop'...
$ git fetch origin 5b9fdbf6354a94d1c7065acb22c9d0cdb14c1d46:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/plasma-desktop
 * [new ref]         5b9fdbf6354a94d1c7065acb22c9d0cdb14c1d46 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5b9fdbf 6.0.3