Fix Claude Code sandbox environment on Linux VMs by subsy · Pull Request #210 · subsy/ralph-tui

subsy · 2026-01-23T16:40:05Z

Summary

This PR fixes Claude Code execution failures on Linux VMs (particularly when running as root) by automatically setting the IS_SANDBOX=1 environment variable when the skipPermissions option is enabled.

Changes

Environment variable handling: When skipPermissions is enabled, the IS_SANDBOX=1 environment variable is now automatically injected into the Claude Code execution environment
Error messaging: Updated the Claude Code troubleshooting guide to include guidance about setting IS_SANDBOX=1 on Linux VMs running as root
Backwards compatibility: The change merges the sandbox environment with any user-provided environment variables, ensuring existing configurations continue to work

Implementation Details

The sandbox environment is conditionally constructed based on the skipPermissions flag
Environment variables are merged using object spread syntax, allowing user-provided env options to override the default sandbox setting if needed
The troubleshooting message now includes a fifth step specifically addressing the Linux VM sandbox requirement

Summary by CodeRabbit

New Features
- Enhanced environment variable handling when permission skipping is enabled to ensure the sandbox flag is propagated across execution paths.
Documentation
- Updated setup guidance with an additional Linux-specific step to ensure the sandbox environment flag is present, especially when running as root.
Tests
- Added tests verifying sandbox environment variable behaviour, including default, explicit, disabled and user-overridden cases.

_{✏️ Tip: You can customize this high-level summary in your review settings.}

…ermissions On Linux VMs (especially running as root), Claude Code requires IS_SANDBOX=1 in the environment when using --dangerously-skip-permissions. Without it, Claude exits with a non-zero code, causing ralph-tui doctor to mark the agent as UNHEALTHY. Automatically inject IS_SANDBOX=1 into the spawned process environment when skipPermissions is enabled. User-provided env vars can still override this if needed. https://claude.ai/code/session_01RESU72861v9zKL3p41DM2V

vercel · 2026-01-23T16:40:10Z

The latest updates on your projects. Learn more about Vercel for GitHub.

1 Skipped Deployment

Project	Deployment	Review	Updated (UTC)
ralph-tui	Ignored	Preview	Jan 23, 2026 5:21pm

coderabbitai · 2026-01-23T16:40:17Z

Walkthrough

When skipPermissions is enabled, the Claude plugin sets IS_SANDBOX=1 and merges it into the spawned CLI process environment across both execute paths. Tests were added to validate the variable is set, omitted, or overridden. Preflight guidance text was updated to include a Linux note.

Changes

Cohort / File(s)	Summary
Claude plugin core `src/plugins/agents/builtin/claude.ts`	Added conditional injection of `IS_SANDBOX=1` into `options.env` when `skipPermissions` is true, applied in both primary and secondary Claude execution paths; updated preflight guidance and example text to mention Linux-specific `IS_SANDBOX` requirement.
Tests for env propagation `tests/plugins/claude-agent.test.ts`	Added tests that spy on `BaseAgentPlugin.prototype.execute` and use a test plugin to assert `IS_SANDBOX` is set when `skipPermissions` is true (explicit/default), absent when false, and can be overridden by user-provided env.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~12 minutes

Poem

🐰 A tiny rabbit hops to say hello,
IS_SANDBOX=1 now helps the workflows flow.
Tests peek inside the env with cheer,
Linux gets a nod — the path is clear.
A small change, softly done — now onward we go! 🥕

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title directly and accurately summarizes the main change: adding IS_SANDBOX environment variable support for Claude Code on Linux VMs, which is the primary focus of both code and test changes.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing touches

📝 Generate docstrings

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

_{Comment @coderabbitai help to get the list of available commands and usage tips.}

codecov · 2026-01-23T16:41:16Z

Codecov Report

❌ Patch coverage is 55.55556% with 4 lines in your changes missing coverage. Please review.
✅ Project coverage is 44.93%. Comparing base (355f086) to head (837c093).
⚠️ Report is 6 commits behind head on main.

Files with missing lines	Patch %	Lines
src/plugins/agents/builtin/claude.ts	55.55%	4 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #210      +/-   ##
==========================================
+ Coverage   44.87%   44.93%   +0.06%     
==========================================
  Files          84       84              
  Lines       24466    24475       +9     
==========================================
+ Hits        10978    10998      +20     
+ Misses      13488    13477      -11

Files with missing lines	Coverage Δ
src/plugins/agents/builtin/claude.ts	`54.82% <55.55%> (+2.63%)`	⬆️

🚀 New features to boost your workflow:

❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

Verifies that: - IS_SANDBOX=1 is set when skipPermissions is true (default) - IS_SANDBOX is not set when skipPermissions is false - User-provided env vars can override the sandbox env Uses a test subclass that spawns /bin/sh to echo the env var, allowing direct verification of environment propagation. https://claude.ai/code/session_01RESU72861v9zKL3p41DM2V

The previous tests spawned /bin/sh to verify IS_SANDBOX propagation, which failed in CI due to environment differences. Rewrite to spy on BaseAgentPlugin.prototype.execute and verify the env options passed to it directly, making the tests deterministic and CI-friendly. https://claude.ai/code/session_01RESU72861v9zKL3p41DM2V

…-Qk9LF Fix Claude Code sandbox environment on Linux VMs

claude and others added 4 commits January 23, 2026 16:45

Merge branch 'main' into claude/fix-vm-unhealthy-error-Qk9LF

7658490

Merge branch 'main' into claude/fix-vm-unhealthy-error-Qk9LF

837c093

subsy merged commit 589efb9 into main Jan 23, 2026
9 checks passed

sakaman pushed a commit to sakaman/ralph-tui that referenced this pull request Feb 15, 2026

Merge pull request subsy#210 from subsy/claude/fix-vm-unhealthy-error…

d587aad

…-Qk9LF Fix Claude Code sandbox environment on Linux VMs

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Fix Claude Code sandbox environment on Linux VMs#210

Fix Claude Code sandbox environment on Linux VMs#210
subsy merged 5 commits intomainfrom
claude/fix-vm-unhealthy-error-Qk9LF

subsy commented Jan 23, 2026 •

edited by coderabbitai bot

Loading

Uh oh!

vercel bot commented Jan 23, 2026 •

edited

Loading

Uh oh!

coderabbitai bot commented Jan 23, 2026 •

edited

Loading

Uh oh!

codecov bot commented Jan 23, 2026 •

edited

Loading

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

Comments

Conversation

subsy commented Jan 23, 2026 • edited by coderabbitai bot Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Summary

Changes

Implementation Details

Summary by CodeRabbit

Uh oh!

vercel bot commented Jan 23, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

coderabbitai bot commented Jan 23, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Walkthrough

Changes

Estimated code review effort

Poem

Uh oh!

codecov bot commented Jan 23, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Codecov Report

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

Comments

subsy commented Jan 23, 2026 •

edited by coderabbitai bot

Loading

vercel bot commented Jan 23, 2026 •

edited

Loading

coderabbitai bot commented Jan 23, 2026 •

edited

Loading

codecov bot commented Jan 23, 2026 •

edited

Loading