$ git clone -n https://src.fedoraproject.org/rpms/polkit-kde.git /var/lib/mock/f42-build-side-1-3566306-46733/root/chroot_tmpdir/scmroot/polkit-kde
Cloning into '/var/lib/mock/f42-build-side-1-3566306-46733/root/chroot_tmpdir/scmroot/polkit-kde'...
$ git fetch origin 1d61d2b6527e715d79ed66d894a140982c2c96b6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/polkit-kde
 * [new ref]         1d61d2b6527e715d79ed66d894a140982c2c96b6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1d61d2b 6.4.0