Add copy to clarify the need to pass `-K` to use cache
Add copy to clarify the need to pass `-K` to use cache

mfikes/planck,mfikes/planck,mfikes/planck,slipset/planck,slipset/planck,mfikes/planck,slipset/planck,slipset/planck,mfikes/planck,mfikes/planck,slipset/planck