Bug Report: stop-hook.ts fails with "spawn /bin/sh ENOENT" error

[nbost130]

I encountered this issue and Claude proposed the following fix. DISCLAIMER: I am not knowledgeable enough to know whether this is the best solution but I wanted to raise awareness so it can be addressed.

Bug Report: stop-hook.ts fails with "spawn /bin/sh ENOENT" error

Description

The stop-hook.ts file fails with the error spawn /bin/sh ENOENT when Claude Code executes the Stop hook in certain contexts.

Root Cause

Lines 524-527 in hooks/stop-hook.ts use Node.js child_process.execSync() to execute shell commands for setting terminal tab titles:

const { execSync } = await import('child_process');
execSync(`printf '\\033]0;${escapedTitle}\\007' >&2`);
execSync(`printf '\\033]2;${escapedTitle}\\007' >&2`);
execSync(`printf '\\033]30;${escapedTitle}\\007' >&2`);

This approach requires spawning a /bin/sh shell process, which can fail in the execution context where Claude Code runs hooks.

Error Message

⏺ Stop [bun ${PAI_DIR}/hooks/stop-hook.ts] failed with non-blocking status code 1: Error
  occurred while executing hook command: spawn /bin/sh ENOENT

Impact

• Hook fails completely when shell spawn fails
• Voice notifications and tab title updates don't work
• Users see error messages on every Claude Code session stop

Proposed Solution

Replace execSync() calls with direct process.stderr.write() using ANSI escape sequences. This approach is:

• Already used elsewhere in the same file (lines 105-130) for the same purpose
• More reliable (no shell process spawning required)
• More performant (no process spawning overhead)
• Functionally identical

Environment

• Claude Code version: 2.0.8
• Bun version: 1.2.23
• macOS Darwin 24.5.0

[danielmiessler]

@claude Can you help with this?

[claude]

Claude finished @danielmiessler's task —— View job • claude/issue-25-20251007-0115 • Create PR ➔

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Tasks Completed

Tasks:

• Read repository guidelines (CLAUDE.md)
• Read and analyze stop-hook.ts
• Implement the fix (replace execSync with process.stderr.write)
• Commit and push changes
• Provide PR URL

Analysis

Found the issue in PAI_DIRECTORY/hooks/stop-hook.ts:

• Lines 524-527 used execSync() which spawns /bin/sh, causing ENOENT errors
• Lines 105-130 showed the correct pattern using process.stderr.write() with ANSI escape sequences

Changes Made

Replaced the problematic code in PAI_DIRECTORY/hooks/stop-hook.ts:518-529:

• Removed the execSync() calls that required spawning /bin/sh
• Replaced with direct process.stderr.write() calls using ANSI escape sequences (\x1b]0;, \x1b]2;, \x1b]30;)
• Removed the shell escaping logic (no longer needed)
• This matches the pattern already used successfully in lines 105-130 of the same file

Benefits

• ✅ No shell process spawning required (fixes the ENOENT error)
• ✅ More reliable execution in all contexts
• ✅ Better performance (no process spawning overhead)
• ✅ Functionally identical output
• ✅ Simplified code (no shell escaping needed)

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Job Run | Branch

[nbost130]

Good to know! I've been learning so much using Claude & other AI tools. Loving it!