"Parallel Build" runs finish subagent work but parent never marks plan todos complete

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1

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

When a Plan is created and Build parallelly is used, subagents appear to start and complete their assigned work, but the plan/todo checklist is not updated: items stay pending/incomplete even though the work finished.

Expected: As each parallel subagent completes, the corresponding todo(s) should flip to done (or otherwise reflect real completion) so the main thread shows accurate status.

Actual: Todos remain unchecked; only the subagent runs seem to terminate. The main agent does not reconcile parallel results back into the todo list.

Steps to Reproduce

Create a plan with multiple todos → use Build parallelly → wait for subagents to finish → observe todo list still unchanged.

Expected Behavior

As each parallel subagent completes, the corresponding todo(s) should flip to done (or otherwise reflect real completion) so the main thread shows accurate status.

Operating System

Windows 10/11

Version Information

Version: 3.4.20 (user setup)
VSCode Version: 1.105.1
Commit: 0cf8b06883f54e26bb4f0fb8647c9500ccb43310
Date: 2026-05-15T02:26:10.351Z
Layout: editor
Build Type: Stable
Release Track: Default
Electron: 39.8.1
Chromium: 142.0.7444.265
Node.js: 22.22.1
V8: 14.2.231.22-electron.0
OS: Windows_NT x64 10.0.26200

For AI issues: which model did you use?

Composer 2

Does this stop you from using Cursor

No - Cursor works, but with this issue

5

Hey, thanks for the report, the repro is clear.

This is a known issue. When parallel subagents finish, the parent agent gets a completion signal but doesn’t get an explicit instruction to update its own todo list, so items can stay stuck in pending or in_progress. The UI just renders what the model says, so this isn’t a rendering bug, it’s an agent prompting limitation.

We’re tracking the issue, but I can’t share an ETA for a fix yet.

As a temporary workaround, after the parallel build finishes, ask the parent agent in chat: “update the todo list based on subagent results”. That usually makes the todos update correctly.

7

Thanks, yes i have started to ask the parent agent to update the todo list.