$ git clone -n https://src.fedoraproject.org/rpms/kwin-x11.git /var/lib/mock/f42-build-side-1-3582503-46885/root/chroot_tmpdir/scmroot/kwin-x11
Cloning into '/var/lib/mock/f42-build-side-1-3582503-46885/root/chroot_tmpdir/scmroot/kwin-x11'...
$ git fetch origin 854b2004d97a77a82730208b22225b9eac89d8b3:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/kwin-x11
 * [new ref]         854b2004d97a77a82730208b22225b9eac89d8b3 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 854b200 Update to 6.4.2.