EACCES: permission denied on Termux/Android - hardcoded /tmp path ignores $TMPDIR

Description

Claude Code fails to execute certain operations on Termux (Android) because it tries to create directories under /tmp/claude/ instead of respecting the $TMPDIR environment variable.

Environment

• Platform: Android (Termux)
• OS: Linux 6.6.77-android15
• Claude Code version: Latest
• $TMPDIR: /data/data/com.termux/files/usr/tmp

Error

EACCES: permission denied, mkdir '/tmp/claude/-data-data-com-termux-files-home/tasks'

Root Cause

On Android/Termux, /tmp exists but is owned by shell:shell with 0771 permissions. Non-root users cannot create directories there. Termux correctly sets $TMPDIR to a writable location (/data/data/com.termux/files/usr/tmp), but Claude Code ignores this environment variable and hardcodes /tmp.

Expected Behavior

Claude Code should use $TMPDIR (or os.tmpdir() in Node.js which respects it) instead of hardcoding /tmp.

Affected Operations

• curl and wget downloads
• Background task execution
• Agent spawning and task delegation - Agents fail to launch because they cannot create task directories
• Any operation that spawns background processes

Impact

This effectively breaks agent-based workflows on Termux/Android, significantly limiting Claude Code's capabilities on mobile devices.

Workaround

Users must run downloads, background tasks, and agent-equivalent operations directly in terminal, bypassing Claude Code entirely.

Suggested Fix

Replace hardcoded /tmp references with:

const os = require('os');
const tmpDir = os.tmpdir(); // Respects $TMPDIR

Or explicitly check process.env.TMPDIR before falling back to /tmp.