Subagent termination does not kill spawned child processes (disk abuse risk)

Description

When a subagent (task agent) is terminated/cancelled during execution, the PowerShell child processes it spawned continue running silently in the background. The subagent's context disappears from the chat, but the disk-scanning script keeps going at 100% I/O. The only way to stop it is to close opencode entirely.

Real incident: A subagent was running a recursive Get-ChildItem scan on an F: drive (mechanical HDD, ~2TB with millions of files). The user manually terminated the subagent and resumed conversation — the script kept running. The F: drive hit 100% disk utilization. The user suspected ransomware and spent significant time debugging before discovering that quitting opencode cleared the issue.

Plugins

None (default install)

OpenCode version

Latest (via npm)

Steps to reproduce

Ask opencode to perform a task that spawns a long-running subagent (e.g., recursive disk scan)
The subagent executes Get-ChildItem -Path F:\ -Recurse in PowerShell
Terminate/cancel the subagent via the UI
Continue editing or re-entering the conversation
Open Task Manager → Disk tab → F: drive stuck at 100% busy
Close opencode entirely → disk activity stops immediately

Screenshot and/or share link

N/A — disk utilization was observed via Windows Task Manager

Operating System

Windows 11

Terminal

PowerShell 5.1 (Windows Terminal)

This issue doesn't fully meet our contributing guidelines.

What needs to be fixed:

The official bug report template was not used. Please use the bug report template which requires: OpenCode version, Operating System, Terminal, and Plugins fields.
No system information is provided (OS, terminal emulator, OpenCode version). This context is important for reproducing and diagnosing the issue.
No steps to reproduce have been provided in a way that includes the specific commands or actions taken (e.g. what long-running script was used, how the subagent was terminated).

Please edit this issue to address the above within 2 hours, or it will be automatically closed.

This issue might be a duplicate of existing issues. Please check:

OpenCode hangs after detached child-process tool call #33363: OpenCode hangs after detached child-process tool call — child processes spawned by shell tools are not cleaned up, causing the CLI to hang
OpenCode executes a child-spawning tool after cancellation #33364: OpenCode executes a child-spawning tool after cancellation — child-spawning side effects persist after user interrupts
v2: shell: no way to stop a running background command #36424: v2: shell: no handle to stop/cancel running background commands — background shell commands have no cancellation mechanism

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Thank you for updating the issue! It now meets our contributing guidelines. We appreciate the clear and detailed bug report.

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Subagent termination does not kill spawned child processes (disk abuse risk) #38564

Description

Plugins

OpenCode version

Steps to reproduce

Screenshot and/or share link

Operating System

Terminal

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Subagent termination does not kill spawned child processes (disk abuse risk) #38564

Description

Description

Plugins

OpenCode version

Steps to reproduce

Screenshot and/or share link

Operating System

Terminal

Activity

github-actions commented on Jul 23, 2026

github-actions commented on Jul 23, 2026

github-actions commented on Sep 22, 2026

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