Fix: Prevent freezing in non-interactive Gemini CLI when debug mode is enabled

[parthasaradhie]

Details

The CLI would hang indefinitely when the DEBUG env is used in non-interactive (e.g., scripting) mode. This was because of waiting for debugger to connect. This change ensures that the debug output mechanism does not block the process flow in headless environments.

Related Issues

Fixes google-github-actions/run-gemini-cli#337

How to Validate

check release-with-gemini.yaml workflow in https://github.com/parthasaradhie/run-gemini-cli/ repo
Action with issue: https://github.com/parthasaradhie/hello-world-rpm/actions/runs/19957624845/job/57230133922
shows

Debugger listening on ws://0.0.0.0:9229/2b4a5dbd-2821-4368-8cc4-7b368241a4ef

Action with issue fixed :
https://github.com/parthasaradhie/hello-world-rpm/actions/runs/19964069457

[gemini-code-assist]

Summary of Changes

Hello @parthasaradhie, 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 resolves an issue where the Gemini CLI would hang indefinitely in non-interactive environments, such as scripting or CI/CD pipelines, when the 'DEBUG' environment variable was present. The changes streamline how debug mode is detected and activated, preventing the CLI from attempting to connect a debugger in headless contexts and thus ensuring smooth execution.

Highlights

• Issue Resolution: Addresses a critical bug where the Gemini CLI would freeze in non-interactive environments (e.g., CI/CD pipelines) when the 'DEBUG' environment variable was set, due to it waiting for a debugger to connect.
• Refined Debug Mode Handling: Refines the logic for detecting and activating debug mode, ensuring that the '--inspect-brk' flag (which causes the hang) is only applied under specific, interactive debugging conditions, and not in headless environments.
• Code Simplification: Removes redundant debug-related logic from 'packages/cli/src/utils/sandboxUtils.ts' for non-development builds, centralizing explicit debug mode activation and '--inspect-brk' flag handling in 'scripts/start.js'.

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[gemini-code-assist]

Code Review

This pull request addresses a critical issue where the CLI could hang in non-interactive environments by making the debug flag activation more specific. My review focuses on two points: first, a potential over-correction that removes a debugging feature which could be preserved while still fixing the bug. Second, an inconsistency in comparison operators between the modified files. The suggested changes aim to fix the bug without losing functionality and improve code consistency.

[github-actions]

Size Change: +70 B (0%)

Total Size: 21.5 MB

ℹ️ View Unchanged

Filename	Size	Change
./bundle/gemini.js	21.5 MB	+70 B (0%)
./bundle/sandbox-macos-permissive-closed.sb	1.03 kB	0 B
./bundle/sandbox-macos-permissive-open.sb	890 B	0 B
./bundle/sandbox-macos-permissive-proxied.sb	1.31 kB	0 B
./bundle/sandbox-macos-restrictive-closed.sb	3.29 kB	0 B
./bundle/sandbox-macos-restrictive-open.sb	3.36 kB	0 B
./bundle/sandbox-macos-restrictive-proxied.sb	3.56 kB	0 B

_{compressed-size-action}

[parthasaradhie]

/gemini review

[gemini-code-assist]

Code Review

This pull request addresses a bug that causes the Gemini CLI to freeze in non-interactive mode when debugging is enabled. The fix involves changing the check for the DEBUG environment variable to be more specific, looking for 'true' or '1' instead of just its presence. This is a good change that correctly targets the intended debug activation. I have one suggestion to improve the maintainability of the new logic by reducing code duplication.