The node dependency logic, why the end node were executed twice

[Fnck]

we are using langgraph v0.0.55, and here is the problem:

• we have a workflow with 2 branches just like start -> A -> B -> end, start -> C -> D -> end, the branches share a same end node here.
• when the workflow is run, the final end node will be executed twice
• I just check the internal func _prepare_next_tasks in venv/Lib/site-packages/langgraph/pregel/init.py line 1540, there seems have no depency check when the code preparing the next task

So here is the problem:
where can I find the dependency related logic in the code, and is the scenario of end node were run twice is expected?
Thank you

[Fnck]

Will debug the sample code in here:
https://langchain-ai.github.io/langgraph/how-tos/branching/#parallel-node-fan-out-and-fan-in
it will tell the truth.

[raminos]

@Fnck did you solve this. I experienced something similar.