[BUG] sandbox Claude Code crashes and OOM-killed by kernel when node_modules exists in project directory

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?

Claude Code crashes and is killed by the Linux OOM killer when node_modules/ is present in a pnpm workspace monorepo. The process balloons to ~25GB RSS and ~119GB virtual memory on a 32GB machine until the kernel terminates it.

Kernel log evidence:

Feb 23 11:21:57 kernel: Out of memory: Killed process 91642 (claude) total-vm:119777372kB, anon-rss:25049716kB, file-rss:160kB, shmem-rss:0kB, UID:1000 pgtables:59580kB oom_score_adj:0

This happens both when:

1. Starting Claude Code in a project that already has node_modules/
2. Running pnpm install during an active session (in a separate terminal)

The Claude Code debug logs (~/.claude/debug/) show no errors — the process simply stops logging as the event loop becomes blocked, then the OOM killer terminates it.

Mitigations attempted with no effect:

• .claudeignore with node_modules
• .gitignore with node_modules + respectGitignore: true
• permissions.deny with Read(./node_modules/**) in project .claude/settings.json

What Should Happen?

Claude Code should not crash after if node_modules/ exist, or ignore node_modules/ for file watching purposes, consistent with .gitignore and .claudeignore patterns. The file watcher should not process directories that are excluded by these ignore files.

Error Messages/Logs

# OOM kill from journalctl:
Feb 23 11:21:57 kernel: Out of memory: Killed process 91642 (claude) total-vm:119777372kB, anon-rss:25049716kB, file-rss:160kB, shmem-rss:0kB, UID:1000 pgtables:59580kB oom_score_adj:0

Steps to Reproduce

1. Clone a Node.js/TypeScript project with dependencies (pnpm workspace monorepo in this case)
2. Ensure .gitignore and .claudeignore both contain node_modules
3. Run pnpm install to create node_modules/
4. Run claude — session hangs or becomes unresponsive
5. Alternative: start claude first, then run pnpm install in another terminal — same result

Claude Model: claude-opus-4-6

Is this a regression?: Unknown — issue has been present since at least version 2.1.50

Claude Code Version: 2.1.50 (Claude Code)

Platform: Anthropic API (direct)

Operating System: Linux 6.8.0-94-generic x86_64 (Ubuntu 22.04)

Terminal/Shell: zsh (xterm-256color)

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.50

Platform

Anthropic API

Operating System

Ubuntu/Debian Linux

Terminal/Shell

Other

Additional Information

• RAM: 32GB + 8GB swap
• Node: v18.20.7
• pnpm: 10.13.1
• inotify max_user_watches: 1048576
• inotify max_user_instances: 1024
• Sandbox: enabled
• MCP servers: 1 custom project MCP server + context7
• Hooks: SessionStart, PreToolUse (Bash), PostToolUse (Edit|Write), Notification
• Plugins: 4 enabled (code-simplifier, security-guidance, building-secure-contracts, solidity-function-audit-team)

<details><summary>~/.claude/settings.json (global)</summary>

{
  "$schema": "https://json.schemastore.org/claude-code-settings.json",
  "respectGitignore": true,
  "cleanupPeriodDays": 7,
  "env": {
    "CLAUDE_CODE_EXPERIMENTAL_AGENT_TEAMS": "1",
    "CLAUDE_CODE_SUBAGENT_MODEL": "sonnet",
    "ENABLE_TOOL_SEARCH": "auto:5",
    "DISABLE_TELEMETRY": "1",
    "DISABLE_ERROR_REPORTING": "1",
    "CLAUDE_CODE_DISABLE_FEEDBACK_SURVEY": "1"
  },
  "includeCoAuthoredBy": false,
  "permissions": {
    "allow": [
      "Bash(forge build)", "Bash(forge test *)",
      "Bash(git log *)", "Bash(git status *)", "Bash(git diff *)",
      "Bash(git show *)", "Bash(git branch *)", "Bash(git remote *)",
      "WebFetch", "WebSearch"
    ],
    "deny": [
      "Read(./.env)", "Read(./.env.*)", "Read(./secrets/**)",
      "Read(~/.ssh/**)", "Read(~/.gnupg/**)", "Read(~/.git-credentials)",
      "Bash(curl *)", "Bash(wget *)", "Bash(rm -rf *)", "Bash(sudo *)",
      "Bash(git push --force*)", "Bash(git reset --hard*)"
    ]
  },
  "model": "opus",
  "hooks": {
    "SessionStart": [{ "matcher": "startup|resume", "hooks": [{ "type": "command", "command": "~/.claude/hooks/session-context.sh", "timeout": 5 }] }],
    "PreToolUse": [{ "matcher": "Bash", "hooks": [{ "type": "command", "command": "~/.claude/hooks/pre-commit-changelog.sh", "timeout": 10 }, { "type": "command", "command": "CMD=$(jq -r '.tool_input.command'); if echo \"$CMD\" | grep -qE 'git[[:space:]]+push.*(main|master)'; then echo 'BLOCKED' >&2; exit 2; fi" }] }],
    "PostToolUse": [{ "matcher": "Edit|Write", "hooks": [{ "type": "command", "command": "~/.claude/hooks/auto-fmt-sol.sh", "timeout": 30 }] }],
    "Notification": [{ "matcher": "permission_prompt|idle_prompt", "hooks": [{ "type": "command", "command": "~/.claude/hooks/notify-attention.sh", "timeout": 5 }] }]
  },
  "sandbox": { "enabled": true, "autoAllowBashIfSandboxed": true },
  "enabledPlugins": {
    "code-simplifier@claude-plugins-official": true,
    "security-guidance@claude-plugins-official": true,
    "building-secure-contracts@trailofbits": true,
    "solidity-function-audit-team@solidity-audit-skills": true
  },
  "alwaysThinkingEnabled": true,
  "autoUpdatesChannel": "latest"
}

</details>

<details><summary>.claude/settings.json (project)</summary>

{
  "permissions": {
    "deny": [
      "Read(./node_modules/**)",
      "Read(./packages/mcp/node_modules/**)"
    ]
  }
}

</details>

<details><summary>.claude/settings.local.json (project local)</summary>

{
  "permissions": {
    "allow": [
      "mcp__context7__resolve-library-id",
      "mcp__context7__query-docs",
      "Bash(tail:*)",
      "Bash(xargs rm -v)",
      "Bash(head:*)",
      "WebFetch(domain:registry.npmjs.org)"
    ]
  }
}