Hey Joe, can you fix simple problem A?
Sure, Sally, no problem! After all it's simple, right?
But A is then found to have dependent sub-problems B and C; B to have dependent sub-problems D, E, and F; and C to have dependent problems G and H.
The problems have to be removed in alphabetical order.
Context: As a software developer, I run into problems like this while working on bugs in complex programs.
I wonder whether there's an English name for this concept.