fix(opencode): robust process exit detection for child processes by NachoFLizaur · Pull Request #15757 · anomalyco/opencode

NachoFLizaur · 2026-03-02T20:05:06Z

Issue for this PR

Closes #14769
Possible related issue that might get fixed by this: #15675 (it seems related based on the description)

Type of change

Bug fix
New feature
Refactor / code improvement
Documentation

What does this PR do?

The bash tool and Process.spawn rely solely on Bun's proc.once("exit") to detect when a child process finishes. In containerized environments, this event is not reliably delivered (due to Bun), causing the completion promise to hang forever, tool calls get permanently stuck at status=running.

The fix removes the runtime dependency on Bun for process exit detection, replacing it with a multi-layer strategy that uses OS-level primitives:

close event: independent signal path from exit in Bun's internals
stdio end events (bash tool only): uses the pipe I/O subsystem, independent of process lifecycle monitoring
Polling watchdog (1s interval): checks proc.exitCode and process.kill(pid, 0) to detect dead processes via OS-level signals, completely bypassing Bun's event system
Server-level watchdog (5s interval in prompt.ts): external safety net that force-completes processes stuck past their timeout

All detection paths funnel through a single done() function guarded by a resolved boolean, ensuring exactly-once Promise resolution.

Also improves Shell.killTree() with an alive() check before escalating from SIGTERM to SIGKILL.

How did you verify your code works?

Polling watchdog isolation tests directly prove exit detection works WITHOUT exit/close events firing (simulates the exact Bun failure mode).

Regression tests verify normal bash tool execution is unaffected by the additional detection layers. Shell.killTree tests verify SIGTERM->alive check->SIGKILL escalation.

I also tested it in containerized opencode serve mode, bash tool calls now complete reliably instead of hanging.

Screenshots / recordings

No UI changes.

Checklist

I have tested my changes locally
I have not included unrelated changes in this PR

github-actions · 2026-03-02T20:05:38Z

The following comment was made by an LLM, it may be inaccurate:

Based on my searches, I found one potentially related PR:

Related PR Found:

fix: resolve memory leaks and zombie processes from missing cleanup handlers #13186 - "fix: resolve memory leaks and zombie processes from missing cleanup handlers"
- fix: resolve memory leaks and zombie processes from missing cleanup handlers #13186
- This PR addresses similar concerns around process cleanup and preventing zombie processes, which is related to the exit detection and proper process lifecycle management that PR fix(opencode): robust process exit detection for child processes #15757 is improving.

All other search results only returned the current PR (#15757) itself. The searches did not find any open PRs that are direct duplicates of this process exit detection fix. PR #13186 is adjacent in addressing process-related issues but focuses on memory leaks and cleanup handlers rather than the specific exit detection problem.

NachoFLizaur · 2026-03-02T20:08:01Z

fixed description according to template

github-actions · 2026-03-02T20:09:40Z

Thanks for updating your PR! It now meets our contributing guidelines. 👍

Port robust process exit detection from PR anomalyco#15757 to fix zombie/stuck child processes in containers where Bun fails to deliver exit events. - Add polling watchdog to bash tool and Process.spawn that detects process exit via kill(pid, 0) when event-loop events are missed - Add process registry (active map) with stale/reap exports for server-level watchdog to detect and clean up stuck bash processes - Improve Shell.killTree with alive() helper and proper SIGKILL escalation after SIGTERM timeout - Add session-level watchdog interval in prompt loop to periodically reap stale bash processes Based on the work in anomalyco#15757. Co-Authored-By: Nacho F. Lizaur <NachoFLizaur@users.noreply.github.com>

Complete the port of PR anomalyco#15757 with remaining pieces: - Add stdio end event redundancy as third fallback for exit detection (fires when pipe file descriptors close, independent of exit events) - Add diagnostic log.info calls at spawn, abort, timeout, and each exit detection path for debugging container issues - Add comprehensive tests: defensive patterns, polling watchdog isolation, Shell.killTree, server-level watchdog (stale/reap), stdio end events, and Process.spawn defensive patterns - Skip truncation tests on Windows (matching upstream) Co-Authored-By: Nacho F. Lizaur <NachoFLizaur@users.noreply.github.com>

Port robust process exit detection from PR anomalyco#15757 to fix zombie/stuck child processes in containers where Bun fails to deliver exit events. - Add polling watchdog to bash tool and Process.spawn that detects process exit via kill(pid, 0) when event-loop events are missed - Add process registry (active map) with stale/reap exports for server-level watchdog to detect and clean up stuck bash processes - Improve Shell.killTree with alive() helper and proper SIGKILL escalation after SIGTERM timeout - Add session-level watchdog interval in prompt loop to periodically reap stale bash processes Based on the work in anomalyco#15757. Co-Authored-By: Nacho F. Lizaur <NachoFLizaur@users.noreply.github.com>

Complete the port of PR anomalyco#15757 with remaining pieces: - Add stdio end event redundancy as third fallback for exit detection (fires when pipe file descriptors close, independent of exit events) - Add diagnostic log.info calls at spawn, abort, timeout, and each exit detection path for debugging container issues - Add comprehensive tests: defensive patterns, polling watchdog isolation, Shell.killTree, server-level watchdog (stale/reap), stdio end events, and Process.spawn defensive patterns - Skip truncation tests on Windows (matching upstream) Co-Authored-By: Nacho F. Lizaur <NachoFLizaur@users.noreply.github.com>

Port robust process exit detection from PR anomalyco#15757 to fix zombie/stuck child processes in containers where Bun fails to deliver exit events. - Add polling watchdog to bash tool and Process.spawn that detects process exit via kill(pid, 0) when event-loop events are missed - Add process registry (active map) with stale/reap exports for server-level watchdog to detect and clean up stuck bash processes - Improve Shell.killTree with alive() helper and proper SIGKILL escalation after SIGTERM timeout - Add session-level watchdog interval in prompt loop to periodically reap stale bash processes Based on the work in anomalyco#15757. Co-Authored-By: Nacho F. Lizaur <NachoFLizaur@users.noreply.github.com>

Complete the port of PR anomalyco#15757 with remaining pieces: - Add stdio end event redundancy as third fallback for exit detection (fires when pipe file descriptors close, independent of exit events) - Add diagnostic log.info calls at spawn, abort, timeout, and each exit detection path for debugging container issues - Add comprehensive tests: defensive patterns, polling watchdog isolation, Shell.killTree, server-level watchdog (stale/reap), stdio end events, and Process.spawn defensive patterns - Skip truncation tests on Windows (matching upstream) Co-Authored-By: Nacho F. Lizaur <NachoFLizaur@users.noreply.github.com>

Port robust process exit detection from PR anomalyco#15757 to fix zombie/stuck child processes in containers where Bun fails to deliver exit events. - Add polling watchdog to bash tool and Process.spawn that detects process exit via kill(pid, 0) when event-loop events are missed - Add process registry (active map) with stale/reap exports for server-level watchdog to detect and clean up stuck bash processes - Improve Shell.killTree with alive() helper and proper SIGKILL escalation after SIGTERM timeout - Add session-level watchdog interval in prompt loop to periodically reap stale bash processes Based on the work in anomalyco#15757. Co-Authored-By: Nacho F. Lizaur <NachoFLizaur@users.noreply.github.com>

Complete the port of PR anomalyco#15757 with remaining pieces: - Add stdio end event redundancy as third fallback for exit detection (fires when pipe file descriptors close, independent of exit events) - Add diagnostic log.info calls at spawn, abort, timeout, and each exit detection path for debugging container issues - Add comprehensive tests: defensive patterns, polling watchdog isolation, Shell.killTree, server-level watchdog (stale/reap), stdio end events, and Process.spawn defensive patterns - Skip truncation tests on Windows (matching upstream) Co-Authored-By: Nacho F. Lizaur <NachoFLizaur@users.noreply.github.com>

rekram1-node · 2026-05-15T03:17:21Z

Automated PR Cleanup

Thank you for contributing to opencode.

Due to the high volume of PRs from users and AI agents, we periodically close older PRs using automated criteria so maintainers can focus review time on the most active and community-supported contributions.

This PR was closed because it matched the following cleanup criteria:

The PR was created more than 1 month ago
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github-actions Bot added contributor needs:compliance This means the issue will auto-close after 2 hours. labels Mar 2, 2026

github-actions Bot removed the needs:compliance This means the issue will auto-close after 2 hours. label Mar 2, 2026

NachoFLizaur force-pushed the fix/bash-process-exit-detection branch from f36ae38 to 9da397e Compare March 3, 2026 06:59

This was referenced Mar 3, 2026

📊 AI CLI 工具社区动态日报 2026-03-03 duanyytop/agents-radar#60

Closed

📊 AI CLI 工具社区动态日报 2026-03-03 duanyytop/agents-radar#65

Closed

NachoFLizaur force-pushed the fix/bash-process-exit-detection branch from 43f75bc to e4b57cf Compare March 6, 2026 11:37

binarydoubling mentioned this pull request Mar 9, 2026

Multiple memory leaks cause unbounded RAM growth during extended TUI usage #16697

Closed

fix(opencode): robust process exit detection for child processes

d603698

NachoFLizaur force-pushed the fix/bash-process-exit-detection branch from 09089e5 to d603698 Compare March 26, 2026 14:12

Merge branch 'dev' into fix/bash-process-exit-detection

9bc816b

NachoFLizaur force-pushed the fix/bash-process-exit-detection branch from e3df5ee to 9bc816b Compare March 27, 2026 17:47

This was referenced Apr 3, 2026

fix: use exit event instead of close to resolve bash tool hang with background processes #20901

Closed

fix: bash tool memory leak #21321

Closed

opencode-agent Bot force-pushed the dev branch from 2f2ed11 to 9f201d6 Compare April 16, 2026 21:55

rekram1-node closed this May 15, 2026

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fix(opencode): robust process exit detection for child processes#15757

fix(opencode): robust process exit detection for child processes#15757
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