$ git clone -n https://src.fedoraproject.org/rpms/kf6-kwindowsystem.git /var/lib/mock/f40-build-2525362-61810/root/chroot_tmpdir/scmroot/kf6-kwindowsystem
Cloning into '/var/lib/mock/f40-build-2525362-61810/root/chroot_tmpdir/scmroot/kf6-kwindowsystem'...
$ git fetch origin e17195e8660c2ba7d2e2621fbd6ff352f38fb3e7:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/kf6-kwindowsystem
 * [new ref]         e17195e8660c2ba7d2e2621fbd6ff352f38fb3e7 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e17195e 6.0.0