[Bug] AgentRearrange drops img on parallel flow steps, but forwards it on sequential ones

[ayaangazali]

Problem

_run_concurrent_workflow accepts img and never uses it:

def _run_concurrent_workflow(self, agent_names, img: str = None, *args, **kwargs):
    ...
    results = run_agents_concurrently(
        agents=agents_to_run,
        task=self.conversation.get_str(),
    )

run_agents_concurrently takes an img parameter — the call just omitted it.

So the same request behaves differently depending on whether its flow contains a comma:

flow "A, B"    ->  A saw img=None,          B saw img=None
flow "A -> B"  ->  A saw img='chart.png',   B saw img='chart.png'

No error, no warning — the agents simply answer a multimodal question without the image.

Why the sync parallel path is the outlier

Two of the three paths already forward it:

• _run_sequential_workflow forwards img
• _run_concurrent_workflow_stream (the async twin) forwards img
• _run_concurrent_workflow did not

Reach

Anything with a parallel step in its flow: AgentRearrange(flow="A, B").run(task, img=...), SequentialWorkflow.run(task, img=...) where the derived flow has one, and SwarmRouter(swarm_type="AgentRearrange").

Verification

after:
flow "A, B"    ->  A saw img='chart.png',   B saw img='chart.png'
flow "A -> B"  ->  A saw img='chart.png',   B saw img='chart.png'

tests/structs/test_agent_rearrange.py — 11 failed / 54 passed, identical on master (that suite makes live LiteLLM calls, so it is red in a sandbox either way; the counts and the failing set match).

One file, one argument.

(Left alone deliberately: the *args/**kwargs on this method also have no destination on run_agents_concurrently. Removing them is a signature change rather than a bug fix, so it did not belong in this diff.)

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