Graph can miss edges about resolvelib HOT 3 CLOSED

can you give an example of this?

from resolvelib.

(the part I'm not following is how wouldd B not know it has a child -- is that if B is abstract? How would it not learn of child A in the pinning round?)

from resolvelib.

So the pinning process is

1. Loop through each abstract requirement.
2. For each abstract requirement, loop through its possible concrete candidates, try whether one of them can be pinned.
3. For each concrete candidate, discover its dependencies and try to merge them with existing constraints. If the merge is successful, the candidate can be pinned.
4. Pin the said concrete candidate.

Since the dependencies of each concrete candidate are fetched lazily, when we try to pin it, we cannot know B depend on A before we reach B in the loop. My mistake was I read A’s constraints too eagerly, before reaching B, therefore even B correctly contributes to A’s constraints, the contribution is not picked up.

from resolvelib.