Crack in Hung Sewer

I have a crack in my PVC drain line just inside where the hung sewer enters the cinder block wall. Unfortunately, the line runs under my deck and would be a bear to access from outside.

My thinking is to use an internal pipe cutter and make the replacement from the inside (not sure if I would try this myself or not ...). Are there other options?

I was also thinking I would add a flexible coupling above the fitting to reduce any future stress on the joint.

Only good news is that the exterior has good drainage (never had any water in the basement) and not much risk in that direction.

Any advice appreciated,

Tom

If you end up using a clamp on coupling, you must use a banded coupler, not a plain neoprene with just 2 clamps. As for the best way to do the actual repair, I'll let others comment on that.