One day my front door suddenly wouldn't open. I can unlock the knob and it
turns, but the latch doesn't retract. I took off the doorknob, and I can
see that the spindle pushes in the thing it's supposed to when it turns, but
it has absolutely no effect on the latch. I never had any warning of this
problem. The knob worked fine before.

I can't figure out any way to get the latch to retract. There's no way to
push something against it from the outside, and I can't get anything around
it from the inside. The best option I can think of is to remove the door
from the hinges (not an easy or attractive option for me).

Is there a simpler way?

Reb