[BUG] lsof zombie processes accumulate after CLI session exits

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?

Description

After Claude Code CLI sessions terminate (normally or abruptly), hundreds of
lsof processes remain running as orphans, gradually degrading system
performance.

Observed behavior

• 1016 orphaned lsof processes found on macOS after several CLI sessions
• All execute: lsof -a -d cwd -bwPln -Ffn -p <PID>
• The target PIDs no longer exist (dead CLI sessions)
• All processes are reparented to PID 1 (init) with state U (uninterruptible

wait)

• Associated temp file (/tmp/claude-XXXX-cwd) already deleted
• Processes accumulate across sessions and are never cleaned up

Root cause (likely)

Claude Code spawns lsof -a -d cwd to monitor the current working directory of
its Node.js process (likely part of the sandbox/security layer). When the
session ends, these child processes are not killed, possibly because:

• No SIGTERM/SIGCHLD handler cleans them up
• They are spawned detached or in a way that survives parent exit
• The temp file they depend on is deleted but the process keeps waiting

Impact

• Hundreds to thousands of zombie processes after a day of usage
• Noticeable macOS performance degradation (memory, process table bloat)
• Requires manual pkill -f "lsof -a -d cwd -bwPln" to recover

Environment

• macOS 15 (Darwin 25.3.0)
• Claude Code CLI (latest as of 2026-03-19)

What Should Happen?

Expected behavior

lsof watcher processes should be terminated when the parent CLI session exits. A signal handler or process group cleanup should ensure no orphans remain.

Error Messages/Logs

Steps to Reproduce

Steps to reproduce

1. Open a Claude Code CLI session (claude in terminal)
2. Work normally (run tools, execute bash commands, etc.)
3. Terminate the session with Ctrl+C + Ctrl+C (double interrupt)
4. Start a new session
5. Repeat throughout the day, sometimes running multiple sessions in parallel
6. After several sessions, check: ps aux | grep -c "lsof -a -d cwd" — count grows with each terminated session and never decreases

Notes

• Normal daily workflow: sequential and sometimes parallel CLI sessions, each terminated via double Ctrl+C
• The lsof processes survive session termination and are never cleaned up
• A full workday can easily produce 1000+ orphaned processes
• Only workaround is manual cleanup: pkill -f "lsof -a -d cwd -bwPln"
• I am currently on the last version, but I worked all week and claudes updates itself several times a day so I don't really know which version cause this trouble.

Claude Model

Opus

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

2.1.79

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

Diagnostic output

  $ claude --version
  2.1.79 (Claude Code)

  $ ps aux | grep -c "lsof -a -d cwd"
  1016

  $ ps -eo pid,ppid,stat,comm,args | grep "lsof -a -d cwd" | head -5
  46511     1 U    lsof  lsof -a -d cwd -bwPln -Ffn -p 45679
  46527     1 U    lsof  lsof -a -d cwd -bwPln -Ffn -p 45679
  53740     1 U    lsof  lsof -a -d cwd -bwPln -Ffn -p 52730
  53736     1 U    lsof  lsof -a -d cwd -bwPln -Ffn -p 52730
  (... 1012 more)

  # Target PIDs no longer exist:
  $ ps -p 45679,52730
    PID  PPID COMM ARGS
  (empty — both processes are dead)

  # All processes are orphaned (PPID=1) and in U (uninterruptible) state
  $ ps -eo stat | grep -c "^U"
  1013