$ git clone -n https://src.fedoraproject.org/rpms/flatpak-kcm.git /var/lib/mock/f42-build-side-1-3583371-46888/root/chroot_tmpdir/scmroot/flatpak-kcm
Cloning into '/var/lib/mock/f42-build-side-1-3583371-46888/root/chroot_tmpdir/scmroot/flatpak-kcm'...
$ git fetch origin 8d90f52b44a1e6fea10b8d3d5c16f4c601a9a49a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/flatpak-kcm
 * [new ref]         8d90f52b44a1e6fea10b8d3d5c16f4c601a9a49a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8d90f52 6.4.2