How would you plug this old weeping drain hole, in a brick/concrete retaining wall
Since it is leaking I would guess it is below grade, lucky it is only a couple of feet. First I would dig out the area at the crack now the tough part , clean the wall at the crack (a pressure washer is handy in this case). I would fill the crack with hydraulic cement and let it cure then coat the area with a water proof coating last refill the hole.