fix(browser): include Chrome stderr and sandbox hint in CDP startup error by veast · Pull Request #29355 · openclaw/openclaw

veast · 2026-02-28T02:47:14Z

Problem

When Chrome fails to start and CDP times out on port 18800 (or any configured port), the error message is:

Failed to start Chrome CDP on port 18800 for profile "openclaw".

This gives users zero diagnostic information. They cannot tell if the issue is:

Chrome crashing due to missing --no-sandbox in a container/root environment
Shared memory (/dev/shm) too small
A GPU/display issue
A port conflict
Something else entirely

This was reported in #29312 where Chrome worked fine when launched manually but failed through OpenClaw.

Fix

Collect Chrome's stderr output and include up to 2000 chars in the error message
On Linux, if browser.noSandbox is not enabled, append a hint suggesting the user try browser.noSandbox: true (common fix for containers and root environments)

Example output after fix

Failed to start Chrome CDP on port 18800 for profile "openclaw".
Hint: If running in a container or as root, try setting browser.noSandbox: true in config.
Chrome stderr:
[0228/103456.789:ERROR:zygote_host_impl_linux.cc(90)] Running as root without --no-sandbox is not supported...

Testing

Existing browser tests unchanged (no behavioral change when Chrome starts successfully)
On failure, error now includes actionable diagnostics

Closes #29312

…rror (openclaw#29312) When Chrome fails to start and CDP times out, the error message previously contained no diagnostic information, making it impossible to determine why Chrome couldn't start (e.g. missing --no-sandbox in containers, GPU issues, shared memory errors). This change: - Collects Chrome's stderr output and includes up to 2000 chars in the error - On Linux, if noSandbox is not set, appends a hint to try browser.noSandbox: true Closes openclaw#29312

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src/browser/chrome.ts

greptile-apps · 2026-02-28T02:53:46Z

Greptile Summary

This PR improves error diagnostics when Chrome fails to start through CDP by collecting stderr output and providing actionable hints.

Key changes:

Captures Chrome's stderr output during the startup phase (limited to 2000 chars to prevent excessive output)
Includes stderr in the error message when CDP fails to start within the 15-second timeout
Adds a Linux-specific hint suggesting browser.noSandbox: true when running in containers or as root (only shown when noSandbox is not already enabled)

Analysis:

No behavioral changes to the success path - existing functionality remains untouched
Proper use of optional chaining (proc.stderr?.on) to handle cases where stderr might be undefined
Memory-bounded stderr collection prevents potential memory issues
Error message construction is clean with conditional hints that only appear when relevant

Confidence Score: 5/5

This PR is safe to merge with no risk
The change is purely additive for error diagnostics without modifying any existing logic paths. The implementation properly handles edge cases (undefined stderr, empty output) and bounds memory usage. No tests need updating because the happy path behavior is unchanged.
No files require special attention

_{Last reviewed commit: fe6e1ce}

…emory leak Named the anonymous listener so it can be removed via proc.stderr.off() once CDP is confirmed reachable. Also clears the stderrChunks array on success so the buffered data is eligible for GC. Fixes the unbounded memory growth reported in code review: a long-lived Chrome process emitting periodic warnings would keep appending to stderrChunks indefinitely since the listener was never removed. Addresses review comment from chatgpt-codex-connector on PR openclaw#29355.

…rror (openclaw#29355) * fix(browser): include Chrome stderr and sandbox hint in CDP startup error (openclaw#29312) When Chrome fails to start and CDP times out, the error message previously contained no diagnostic information, making it impossible to determine why Chrome couldn't start (e.g. missing --no-sandbox in containers, GPU issues, shared memory errors). This change: - Collects Chrome's stderr output and includes up to 2000 chars in the error - On Linux, if noSandbox is not set, appends a hint to try browser.noSandbox: true Closes openclaw#29312 * chore(browser): format chrome startup diagnostics * fix(browser): detach stderr listener after Chrome starts to prevent memory leak Named the anonymous listener so it can be removed via proc.stderr.off() once CDP is confirmed reachable. Also clears the stderrChunks array on success so the buffered data is eligible for GC. Fixes the unbounded memory growth reported in code review: a long-lived Chrome process emitting periodic warnings would keep appending to stderrChunks indefinitely since the listener was never removed. Addresses review comment from chatgpt-codex-connector on PR openclaw#29355. * changelog: note cdp startup diagnostics improvement --------- Co-authored-by: Vincent Koc <vincentkoc@ieee.org> Co-authored-by: 派尼尔 <painier@openclaw.ai>

openclaw-barnacle bot added the size: XS label Feb 28, 2026

chatgpt-codex-connector bot reviewed Feb 28, 2026

View reviewed changes

src/browser/chrome.ts Show resolved Hide resolved

vincentkoc and others added 4 commits March 1, 2026 22:19

chore(browser): format chrome startup diagnostics

cf9cc5c

Merge branch 'main' into fix/browser-cdp-startup-diagnostics

c6f071d

changelog: note cdp startup diagnostics improvement

a0aa2e2

vincentkoc merged commit 281494a into openclaw:main Mar 2, 2026
26 checks passed

vincentkoc mentioned this pull request Mar 2, 2026

Fix/browser cdp proxy bypass #31204

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vabole mentioned this pull request Mar 2, 2026

ops: decision needed for upstream sync (1 disputed files) vabole/openclaw#5

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github-actions bot mentioned this pull request Mar 2, 2026

📡 Upstream Digest — 2026-03-02 08:35 UTC curtismercier/openclaw-mods#160

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fix(browser): include Chrome stderr and sandbox hint in CDP startup error#29355

fix(browser): include Chrome stderr and sandbox hint in CDP startup error#29355
vincentkoc merged 5 commits intoopenclaw:mainfrom
veast:fix/browser-cdp-startup-diagnostics

veast commented Feb 28, 2026

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veast commented Feb 28, 2026

Problem

Fix

Example output after fix

Testing

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greptile-apps bot commented Feb 28, 2026

Greptile Summary

Confidence Score: 5/5

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