fix(cli): treat SANDBOX=0/false as not inside sandbox

[MohammedADev]

Summary

Fixes sandbox initialization logic so SANDBOX='0' and SANDBOX='false' are not treated as “already inside sandbox”.

before any non-empty SANDBOX value short circuited the sandbox setup. This could unintentionally bypass explicit sandbox requests (for example, GEMINI_SANDBOX='docker').

Details

Root cause
Inpackages/cli/src/config/sandboxConfig.ts, the inside-sandbox guard used a generic truthy check:
if (process.env['SANDBOX']) return ''

Because '0' is a non-empty string, it evaluated truthy and incorrectly disabled sandbox initialization.

Related Issues

fixes #21600

How to Validate

npm run test --workspace @google/gemini-cli -- src/config/sandboxConfig.test.ts
Confirm test passes, including:
should not treat SANDBOX='0' as already inside sandbox

Optional manual behavior check if you want,
Set SANDBOX=0
Set GEMINI_SANDBOX=docker
Confirm sandbox config no longer gets skipped due to the inside the sandbox guard.

Pre-Merge Checklist

• Updated relevant documentation and README (if needed)
• Added/updated tests (if needed)
• Noted breaking changes (if any)
• Validated on required platforms/methods:
  • MacOS
    • npm run
    • npx
    • Docker
    • Podman
    • Seatbelt
  • Windows
    • npm run
    • npx
    • Docker
  • Linux
    • npm run
    • npx
    • Docker

[gemini-code-assist]

Summary of Changes

Hello, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request addresses a critical bug in the CLI's sandbox configuration where non-empty string values for the SANDBOX environment variable, such as '0' or 'false', were incorrectly treated as truthy, causing the sandbox setup to be skipped. The changes ensure that the system accurately determines whether it's already within a sandbox, allowing explicit sandbox requests to be honored as intended.

Highlights

• Sandbox Environment Variable Handling: Modified the sandbox initialization logic to correctly interpret SANDBOX='0' and SANDBOX='false' as indicators that the environment is not already sandboxed. This prevents unintended bypasses of explicit sandbox configurations.

Changelog

• packages/cli/src/config/sandboxConfig.test.ts
  • Added a new test case to verify that SANDBOX='0' does not trigger the "already inside sandbox" condition, ensuring proper sandbox initialization.
• packages/cli/src/config/sandboxConfig.ts
  • Modified the getSandboxCommand function to explicitly check for SANDBOX environment variable values of '0' or 'false' (case-insensitive) to correctly identify when the system is not already in a sandbox.

Activity

• The author has provided detailed steps for validation, including running specific tests and an optional manual behavior check.
• The pre-merge checklist indicates that relevant documentation and tests have been updated, and the changes have been validated on Windows (npm run) and Linux (npm run).

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[gemini-code-assist]

Code Review

This pull request correctly addresses a bug where SANDBOX values of '0' or 'false' were improperly treated as being inside a sandbox. The logic change is sound and is accompanied by a new test case that validates the fix. My review includes one suggestion to align the new test with the repository's testing conventions.

[MohammedADev]

Hi everyone, bumping this PR for code owner review #21601

This has been pending for ~2 weeks and is currently blocked on required maintainer approval. All prior feedback has been addressed and the branch is up to date.

Could someone take a look when available? Thanks in advance!

[gemini-cli]

Hi there! Thank you for your interest in contributing to Gemini CLI.

To ensure we maintain high code quality and focus on our prioritized roadmap, we have updated our contribution policy (see Discussion #17383).

We only guarantee review and consideration of pull requests for issues that are explicitly labeled as 'help wanted'. All other community pull requests are subject to closure after 14 days if they do not align with our current focus areas. For this reason, we strongly recommend that contributors only submit pull requests against issues explicitly labeled as 'help-wanted'.

This pull request is being closed as it has been open for 14 days without a 'help wanted' designation. We encourage you to find and contribute to existing 'help wanted' issues in our backlog! Thank you for your understanding and for being part of our community!