I am knocking on wood as I write this but it hasn't failed us yet. We've done it with two separate coops and no issues. Good luck. I covered it with dirt once and with pea gravel the second time.
When we built our coop we attached hardware cloth to the lower portion of the wall and then bent it out and down making a backward L so 12 inches were lying flat on the ground. We then buried the cloth that was outside the coop. This prevents anything from digging under the run or coop. I hope...