[core][aDAG] Non-dag output cannot be an input of other dag

[rkooo567]

What happened + What you expected to happen

not sure if it is intended. But we cannot pass non-dag-value to be an input of other dag.

Versions / Dependencies

master

Reproduction script

import ray
ray.init()

from ray.dag import InputNode

@ray.remote
class A:
    def g(self, i):
        return 1
    
    def f(self, *a):
        print(a)


a = A.remote()
actors = [A.remote() for _ in range(4)]


with InputNode() as inp:
    activations = []
    for i, actor in enumerate(actors):
        activations.append((actor.g.bind(inp), i))
    dag = a.f.bind(*activations)
adag = dag.experimental_compile()
print(ray.get(adag.execute(1)))

Issue Severity

None