$ git clone -n https://src.fedoraproject.org/rpms/kf6-kimageformats.git /var/lib/mock/f42-build-3426647-45197/root/chroot_tmpdir/scmroot/kf6-kimageformats
Cloning into '/var/lib/mock/f42-build-3426647-45197/root/chroot_tmpdir/scmroot/kf6-kimageformats'...
$ git fetch origin 21fc3d1d1a1b4480a8efb78908ce64a841290011:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/kf6-kimageformats
 * [new ref]         21fc3d1d1a1b4480a8efb78908ce64a841290011 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 21fc3d1 Rebuild for KDE respin