[BUG] Background tasks ignore $TMPDIR and hardcode /tmp/claude/

see also https://github.com/anthropics/claude-code/issues/15637 for same issue on a diff platform

Additional Finding: Termux Path Sanitization Variant

A related issue has been discovered on Termux (Android) that stems from the same root cause. See #15801.

Termux-Specific Problem: The path sanitization logic (replacing / with -) creates invalid paths on systems with deeply nested HOME directories.

Example:

• HOME: \/data/data/com.termux/files/home\
• Sanitized: \-data-data-com-termux-files-home\
• Invalid Path: \/tmp/claude/-data-data-com-termux-files-home/tasks\

Both issues (#15700 and #15801) would be fixed by using XDG Base Directory Specification (\~/.cache/claude/tasks\) or properly hashing the HOME path instead of character replacement.

Platform: Termux on Android ARM64
Reporter: User with TalkBack accessibility needs

@claude any fix you'd suggest for this?

It seems this propagated to agents, can't run them this morning, most likely due to 2.1.0

To work around this problem, I did this:

:; claude --version
2.1.1 (Claude Code)

This is the version with the bug.

First thing, disable auto update by adding this to ~/.claude/settings.json:

  "env": {
    "DISABLE_AUTOUPDATER": "1"
  }

If you are still on version 2.0.76 you're good.

If you are on 2.1.1 then you also have to do this:

:; npm install @anthropic-ai/claude-code@2.0.76

And then verify:

:; claude --version
2.0.76 (Claude Code)

@andersglindstrom this solution was described in the termux post and worked for me:
sed -i "s|/tmp/claude|/data/data/com.{CUSTOM_TMP_PATH}|g" cli.js

I asked Claude to find cli.js referencing the issue and I have a custom command like this that I run after each update

I can confirm replacing the hardcoded path with a usable one fixed subagents.

2.1.5 seems to have made things worse and patch no longer works.

@Lectem we investigated this and there is now a fix:
The fix is working (directories exist). What exactly is the issue you're experiencing? Can you describe what "doesn't work anymore" means - is there an error message?

Let me also check if there are newer patterns in the code that might need patching:

● Bash(grep -c 'CLAUDE_CODE_TMPDIR' "/mnt/nw/home/c.dumas/.nvm/versions/node/v22.17.0/lib/node_modules/@anthropic-ai/claude-code/cli.js")
⎿ 3

● Good news - newer versions of Claude Code support CLAUDE_CODE_TMPDIR environment variable! Instead of patching the binary, you can now use this cleaner approach:

export CLAUDE_CODE_TMPDIR=/run/user/$(id -u)

Add this to your ~/.bashrc or ~/.zshrc and it should work without needing to patch cli.js after each update.

What specific error are you seeing? That will help me determine if there's another issue at play.

I was getting such messages:

Bash(rm -rf build && CMAKE_C_COMPILER_LAUNCHER=ccache CMAKE_CXX_COMPILER_LAUNCHER=ccache cmake -B build -G Ninja 2>&1 | tail -20) ⎿  Error: EACCES: permission denied, mkdir '/tmp/claude/-data-data-com-termux-files-h ome-code-myproject/tasks'

And the workaround mentioned here https://github.com/anthropics/claude-code/issues/15700#issuecomment-3723281340 would make Claude code freeze after a few seconds. (it could also be another bug of 2.1.5 I guess)

In any case it seems that CLAUDE_CODE_TMPDIR works, this should be documented or set properly to read $TMPDIR by default.

Update: Partial Workaround & Root Cause Analysis

Tested Environment Variable Fix (Incomplete):
Setting export TMPDIR="\$HOME/.cache/tmp" in .bashrc partially works for direct commands but does not fix background task execution.

Confirmed Root Cause: Claude Code hardcodes /tmp/claude in the Node.js process itself, not respecting the TMPDIR environment variable even when set globally.

Evidence:

• ✅ Simple foreground commands execute successfully
• ❌ Background tasks with run_in_background: true still fail
• ❌ Long-running operations still fail despite TMPDIR being set

Fix Recommendation:
Replace hardcoded paths with require('os').tmpdir() throughout codebase. This will:

1. Respect TMPDIR environment variable globally
2. Use platform-appropriate temp directories (Termux, containers, restricted environments)
3. Fix background agent execution

I work with scientists in a shared computing environment. This bug is causing some collisions for us, too. The CLAUDE_CODE_TMPDIR workaround was effective, but respecting the main TMPDIR would be more idiomatic for the HPC space. Thanks!

Verified: Still Failing on v2.1.11 - Background Tasks Non-Functional

Environment

• Claude Code: 2.1.11 (Latest)
• Platform: Android 13 (aarch64, Samsung device)
• OS: Linux 5.15.178-android13-8
• $TMPDIR Status: NOT respected

Confirmed Issue

Background task system completely broken - same error as reported:

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

Test Case: Background Task Spawn

Task tool with run_in_background: true

Result: ❌ Fails immediately

Current Status

• /tmp/claude hardcoding NOT FIXED in v2.1.11
• Environment variable $TMPDIR still IGNORED
• No fallback to os.tmpdir() implemented

Impact on Users

• Cannot use run_in_background: true parameter
• Agents cannot spawn (they need task directory)
• Multi-agent workflows impossible on Termux/Android

The update did NOT address this issue. Still waiting for environment variable support.

@salviz CLAUDE_CODE_TMPDIR is the env variable workaround

Additional confirmation from Termux user

Same issue here. My configuration:

# ~/.profile
export TMPDIR="$HOME/.cache/tmp"
export CLAUDE_CODE_TMPDIR="$HOME/.claude-tmp"

Both directories exist and are writable. Claude Code ignores both and still tries /tmp/claude/....

Test Results

| Variable | Set | Directory Exists | Respected by Claude Code |
|----------|-----|------------------|--------------------------|
| TMPDIR | ✓ | ✓ | ❌ |
| CLAUDE_CODE_TMPDIR | ✓ | ✓ | ❌ |

Environment

• Platform: Termux (Android 13)
• Node.js: v24.13.0
• Error: EACCES: permission denied, mkdir '/tmp/claude/-data-data-com-termux-files-home/tasks'

This confirms the path is hardcoded in the CLI, not read from environment or os.tmpdir().

Affected Operations

• All background tasks
• Agent spawning (Task tool)
• Any operation using run_in_background

Request

This issue and its 7+ duplicates have been open since late December 2025. Can we get an ETA on when os.tmpdir() support will be added?

---
Reported from Termux (accessibility user)

I see the "stale" tag on this issue, but the issue is still very much present in the latest version v2.1.81

I see the "stale" tag on this issue, but the issue is still very much present in the latest version v2.1.81

Try setting CLAUDE_CODE_TMPDIR to something else (in your home directory for example) before you invoke Claude Code. And, inside Claude Code, instruct it to set TMPDIR to CLAUDE_CODE_TMPDIR whenever it invokes bash. This has worked for me. The alternative, if you can be bothered, is to run Claude Code in a Docker container so it has its own private /tmp. Not ideal but it works.