Before I enabled it there was an operation not permitted error. Now I have added the ubuntu-unprivileged-overlayfs.patch on archlinux distro I am still getting an error.
$ lxc-copy -n base-arch -N snap1 -B overlayfs -s
lxc-copy: base-arch: storage/overlay.c: ovl_mount: 658 Invalid argument - Failed to mount "/home/user1/.local/share/lxc/base-arch/rootfs" on "/usr/lib/lxc/rootfs" with options "upperdir=/home/user1/.local/share/lxc/snap1/delta0,lowerdir=/home/user1/.local/share/lxc/base-arch/rootfs": Invalid argument
clone failed