[BUG] All Bash tool commands hang indefinitely — no child process is ever spawned (macOS, v2.1.228)

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Every Bash tool invocation hangs indefinitely and never returns, including echo "hello". Non-bash tools (Read, Write, Edit, Glob, Grep) work normally. This has persisted since 2026-07-09.

The key finding: no child process is ever created. While a Bash call is hanging, ps -ef shows the claude process with zero children — the shell that would run the command was never spawned. A sample of the hanging process shows the main thread parked in kevent64 for 8206 of 8244 samples, waiting on a notification that never fires. So this is not a slow command or a stuck subprocess; execution never reaches the shell.

Environment

• macOS (Apple Silicon)
• Claude Code v2.1.220 and v2.1.228 (both reproduce)
• Installed via npm global (/opt/homebrew/lib/node_modules/@anthropic-ai/claude-code), no mixed installation
• Reproduces in both the CLI and the Claude desktop app

Steps to Reproduce

1. Start claude in any directory
2. Ask it to run echo "hello" with run_in_background unset
3. Approve the permission prompt
4. The tool never returns

Ruled Out

• PreToolUse hooks — removed all hooks from settings.json, no change
• CLAUDE_CODE_DISABLE_BACKGROUND_TASKS=1 in settings.json env — background execution stops, hang remains
• ~/.claude/shell-snapshots — deleted, no change
• Desktop-app specificity — CLI reproduces identically
• Version — v2.1.220 and v2.1.228 both reproduce
• Installation — npm uninstall -g followed by npm install -g did not help (unlike #41983, where reinstalling resolved it)
• /doctor runs fine and reports nothing related to Bash

Expected Behavior

Bash commands execute and return output within a reasonable time, or fail with an error.

Additional Notes

Possibly related: #41983, #62115, #62292. A stack sample from the hanging process is available on request.

What Should Happen?

Bash commands execute and return output within a reasonable time, or fail with an explicit error. Even a trivial command like echo "hello" should return in well under a second.

Error Messages/Logs

No error message is produced — the tool simply never returns.

Process state while hanging (`ps -ef | grep claude`), showing zero child processes:

  502 77522 77504   0 10:02AM ttys000    0:59.93 claude

Main thread stack from `sample <pid> 10` (8244 samples, 8206 parked in kevent64):

    8244 Thread_5664904   DispatchQueue_1: com.apple.main-thread  (serial)
    + 8244 start  (in dyld) + 6992
    +   8244 ??? (in claude.exe) load address 0x104b34000 + 0xa28354
    +     ...
    +             ! : 8206 ??? (in claude.exe) load address 0x104b34000 + 0x7f9200
    +             ! : | 8206 kevent64  (in libsystem_kernel.dylib) + 8

Steps to Reproduce

1. Start Claude Code in any directory: claude
2. In the chat, send: Run this one command with the Bash tool. Do not set run_in_background: echo "hello"
3. Approve the permission prompt
4. The Bash tool never returns. It has to be interrupted with Esc.

To confirm no child process is spawned, run this in a separate terminal while the call is hanging:

ps -ef | grep -i claude | grep -v grep

The claude process appears with no children.

Claude Model

Not sure / Multiple models

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.228

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

This has been reproducing continuously since 2026-07-09, across multiple Claude Code versions. It is not intermittent — every Bash call hangs, every time.

Diagnostics performed over two sessions, all of which failed to change the behavior:

• Removed all PreToolUse hooks from ~/.claude/settings.json
• Set CLAUDE_CODE_DISABLE_BACKGROUND_TASKS=1 in the settings env block (background execution stopped; the hang did not)
• Deleted ~/.claude/shell-snapshots
• Tested both the CLI and the Claude desktop app (identical behavior)
• Tested v2.1.220 and v2.1.228
• Ran npm uninstall -g @anthropic-ai/claude-code then npm install -g @anthropic-ai/claude-code
• Ran /doctor, which completed normally and reported nothing related to Bash

Installation is npm global only (/opt/homebrew/lib/node_modules/@anthropic-ai/claude-code); there is no native-installer copy on this machine. The full sample output is available if it would help.