zed-industries/zed · warning

User canceled

Error message

User canceled

What it means

SubagentPromptResult::Cancelled maps to this error: the user interrupted the subagent's run (stop button or cancellation propagated from the parent), so no result content is produced. It is a control-flow outcome, not a defect.

Source

Thrown at crates/agent/src/agent.rs:3419

                        .last_message()
                        .and_then(|message| {
                            let content = message.as_agent_message()?
                                .content
                                .iter()
                                .filter_map(|c| match c {
                                    AgentMessageContent::Text(text) => Some(text.as_str()),
                                    _ => None,
                                })
                                .join("\n\n");
                            if content.is_empty() {
                                None
                            } else {
                                Some( content)
                            }
                        })
                        .context("No response from subagent")
                }),
                SubagentPromptResult::Cancelled => Err(anyhow!("User canceled")),
                SubagentPromptResult::Error(message) => Err(anyhow!("{message}")),
                SubagentPromptResult::ContextWindowWarning => {
                    thread.update(cx, |thread, cx| thread.cancel(cx)).await;
                    Err(anyhow!(
                        "The agent is nearing the end of its context window and has been \
                         stopped. You can prompt the thread again to have the agent wrap up \
                         or hand off its work."
                    ))
                }
            };

            parent_thread
                .update(cx, |parent_thread, cx| {
                    parent_thread.unregister_running_subagent(&subagent_session_id, cx)
                })
                .ok();

            result

View on GitHub (pinned to bc538def45)

Solutions

1. Handle this error as 'cancelled' in the UI (show a stopped state) rather than as a failure.
2. Do not retry automatically — the user chose to stop.
3. Distinguish it from SubagentPromptResult::Error when presenting results.

match subagent_prompt_result {
    Err(e) if e.to_string() == "User canceled" => {
        // user abort: show stopped state, no retry
    }
    Err(e) => return Err(e),
    Ok(output) => { /* use output */ }
}

When it happens

Trigger: The user presses stop while a subagent is running; the parent thread is cancelled and cancellation reaches the subagent's prompt.

Common situations: Any user abort of a long-running subagent task; closing the parent run mid-subagent.

Related errors

• The agent is nearing the end of its context window and has b
• Parent thread no longer exists
• Maximum subagent depth ({}) reached
• No subagent session found with id {session_id}
• Resuming subagent sessions is not supported

AI-assisted analysis of zed-industries/zed@bc538def45 (2026-08-16). Data as JSON: /api/errors/e2e7e3c61ef9455a. Report an issue: GitHub.