fix: ignore VSCode inspector env vars in standalone executables

[robobun]

Summary

• BUN_INSPECT, BUN_INSPECT_CONNECT_TO, and BUN_INSPECT_PRELOAD environment variables are now ignored when running as a bun build --compile standalone executable
• BUN_OPTIONS (e.g. BUN_OPTIONS=--inspect) continues to work as before, so users can still explicitly enable the inspector in standalone binaries

Motivation

When VSCode's Bun extension opens a "JavaScript Debug Terminal", it sets BUN_INSPECT, BUN_INSPECT_NOTIFY, and BUN_INSPECT_CONNECT_TO in the terminal environment. Running a standalone executable in that terminal would unexpectedly enable the inspector — and with ?break=1, hang indefinitely waiting for a debugger connection. Standalone executables are end-user programs that should not be affected by IDE debug instrumentation.

Test plan

• New test verifies BUN_INSPECT with ?break=1 is ignored in standalone (previously would hang)
• New test verifies BUN_OPTIONS=--smol still works in standalone via process.execArgv
• Test fails on system bun (confirming behavioral change) and passes on debug build

🤖 Generated with Claude Code

[robobun]

^{Updated 11:51 PM PT - Feb 28th, 2026}

❌ Your commit 1c2b1bec has 5 failures in Build #38389 (All Failures):

• test/integration/next-pages/test/dev-server.test.ts - 1 failing on 🍎 14 aarch64
• test/integration/next-pages/test/dev-server.test.ts - 1 failing on 🍎 13 aarch64
• test/bundler/bundler_compile_autoload.test.ts - 1 failing on 🐧 13 x64-asan
• test/bundler/bundler_compile_autoload.test.ts - 1 failing on 🐧 13 x64-asan
• cmake/scripts/DownloadZig.cmake - cmake error on 🪟 x64-baseline - build-zig
• cmake/scripts/DownloadUrl.cmake - cmake warning on 🪟 x64-baseline - build-zig
• cmake/scripts/DownloadUrl.cmake - cmake warning on 🪟 x64-baseline - build-zig
• annotation error on 🪟 x64-baseline - build-zig

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🧪   To try this PR locally:

bunx bun-pr 27662

That installs a local version of the PR into your bun-27662 executable, so you can run:

bun-27662 --bun

[coderabbitai]

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📥 Commits

Reviewing files that changed from the base of the PR and between 7ef4b1b and 1c2b1be.

📒 Files selected for processing (3)

• src/bun.js/VirtualMachine.zig
• src/cli/Arguments.zig
• test/cli/inspect/standalone-inspect.test.ts

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Walkthrough

Modifies debugger configuration and inspector preload handling to detect and bypass environment variables in standalone mode. Adds tests verifying that BUN_INSPECT environment variables are ignored in standalone executables while BUN_OPTIONS remains functional.

Changes

Cohort / File(s)	Summary
Debugger and Inspector Configuration src/bun.js/VirtualMachine.zig, src/cli/Arguments.zig	Adds standalone mode detection to bypass BUN_INSPECT and BUN_INSPECT_PRELOAD environment variables in standalone executables, with comments explaining that BUN_OPTIONS remains functional through the enable path.
Standalone Inspection Tests test/cli/inspect/standalone-inspect.test.ts	Introduces test suite verifying BUN_INSPECT is ignored in standalone executables while BUN_OPTIONS options remain functional.

🚥 Pre-merge checks | ✅ 2

✅ Passed checks (2 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately summarizes the main change: ignoring VSCode inspector environment variables in standalone executables, which is the primary objective of this PR.
Description check	✅ Passed	The description provides clear sections addressing 'What does this PR do?' (Summary and Motivation) and 'How did you verify your code works?' (Test plan), exceeding the minimal template requirements.

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[claude]

LGTM - small, well-motivated fix that correctly suppresses VSCode debug env vars in standalone executables while preserving BUN_OPTIONS.

Extended reasoning...

Overview

This PR modifies two source files (VirtualMachine.zig and Arguments.zig) and adds one test file. In VirtualMachine.zig, when configureDebugger runs and the process is a standalone executable (standalone_module_graph != null), BUN_INSPECT and BUN_INSPECT_CONNECT_TO are replaced with empty strings so neither the .unspecified unix nor connect_to branches activate. In Arguments.zig, BUN_INSPECT_PRELOAD is similarly nulled out when StandaloneModuleGraph.get() != null. The .enable path (used by BUN_OPTIONS=--inspect) is unaffected since it flows through the CLI flag, not the env vars.

Security risks

No security concerns. This change reduces attack surface by preventing environment-variable-driven debugger activation in standalone binaries, which are end-user programs.

Level of scrutiny

This is production-critical runtime code, but the change is minimal (two conditional expressions plus one null check) and the logic is easy to verify. The empty-string and null fallbacks cleanly disable the env-var paths without affecting any other control flow.

Other factors

The new test covers both the suppression case (BUN_INSPECT with break=1 no longer hangs) and the pass-through case (BUN_OPTIONS still works). No bugs found by the automated bug hunting system. No outstanding reviewer comments to address.