Claude Code / AI Coding Tools

Claude Code --settings EACCES permission denied on shared macOS when two user accounts share a Mac

Fix Claude Code EACCES error when running --settings on macOS with multiple user accounts sharing the same machine Includes evidence for Claude Code troubleshooting demand.

Source-backed Last updated May 14, 2026 1 source Needs local verification

Category: AI Coding Tools
Error signature: EACCES: permission denied, mkdir '/tmp/claude-code-' — --settings writes cache to shared /tmp/
Quick fix: Compare the failing environment with a known working setup, then change one configuration value at a time.
Updated: May 14, 2026
Verification status: Source-backed
Evidence: 1 public source URL

Before you change production

This page includes public source URLs in the imported troubleshooting record. Compare those references with your version and environment before applying changes.

Reproduce the smallest failing action and save non-secret logs before changing configuration.
Check versions for Claude Code, related SDKs, package managers, CI runners, and hosting providers.
Change one setting or dependency at a time, then rerun the same failing command or request.
Avoid destructive commands, credential rotation, billing changes, or security relaxations without a rollback plan.

What this error means

EACCES: permission denied, mkdir '/tmp/claude-code-' — --settings writes cache to shared /tmp/ is a Claude Code failure pattern reported for developers trying to fix claude code eacces error when running --settings on macos with multiple user accounts sharing the same machine. Based on the imported evidence, treat this as a tool-specific troubleshooting page rather than a generic API error.

Why this happens

Claude Code CLI uses /tmp/ for cache directories. When two macOS user accounts share a machine, the second user gets EACCES because the first user's temp files exist with different ownership. No workaround provided.

Common causes

Shared Mac environments (labs, CI runners, family machines) trigger permission conflicts when Claude Code writes cache to world-shared /tmp/. Users see cryptic EACCES with no obvious fix.
Claude Code CLI uses /tmp/ for cache directories. When two macOS user accounts share a machine, the second user gets EACCES because the first user's temp files exist with different ownership. No workaround provided.

Quick fixes

Confirm the exact error signature matches EACCES: permission denied, mkdir '/tmp/claude-code-' — --settings writes cache to shared /tmp/.
Check the Claude Code account, local tool state, and provider configuration involved in the failing workflow.
Compare the failing environment with a known working setup, then change one configuration value at a time.

Platform/tool-specific checks

Verify the command, editor, extension, or API client that produced the error.
Compare local settings with CI, deployment, or editor-level settings when the error appears in only one environment.
Avoid deleting credentials, local model data, or project settings until the failing scope is clear.

Step-by-step troubleshooting

Capture the exact error message and the command, editor action, or request that triggered it.
Check whether the failure is account/auth, quota/rate, model/provider, local runtime, or deployment configuration.
Review the source evidence below and compare it with your environment.
Apply one change at a time and rerun the smallest failing action.
Keep the working fix documented for the team or deployment environment.

How to prevent it

Keep provider/tool configuration documented.
Record non-secret diagnostics such as tool version, provider name, model name, and command path.
Add a lightweight check before CI or production workflows depend on the tool.

Diagnostic flow for this page

Match EACCES: permission denied, mkdir '/tmp/claude-code-' — --settings writes cache to shared /tmp/ exactly before applying the quick fix.
Compare the failing environment with Claude Code versions, account scope, provider settings, and deployment context.
Check the listed common causes in order, starting with the cause that best matches your logs.
Use the evidence status below to decide whether to confirm against public sources or official documentation.
Apply one reversible change, rerun the smallest failing action, and keep rollback notes.

FAQ

What does EACCES: permission denied, mkdir '/tmp/claude-code-' — --settings writes cache to shared /tmp/ mean in Claude Code?

EACCES: permission denied, mkdir '/tmp/claude-code-' — --settings writes cache to shared /tmp/ indicates the workflow described by "Claude Code --settings EACCES permission denied on shared macOS when two user accounts share a Mac" failed in a AI Coding Tools context. Start by confirming the exact signature and the component that emitted it.

What should I check first for EACCES: permission denied, mkdir '/tmp/claude-code-' — --settings writes cache to shared /tmp/?

Check whether this cause matches your environment: Shared Mac environments (labs, CI runners, family machines) trigger permission conflicts when Claude Code writes cache to world-shared /tmp/. Users see cryptic EACCES with no obvious fix.

Is the EACCES: permission denied, mkdir '/tmp/claude-code-' — --settings writes cache to shared /tmp/ guidance source-backed?

The "Claude Code --settings EACCES permission denied on shared macOS when two user accounts share a Mac" page is labeled source-backed. It has 1 public source URL from github.com, so use that evidence status when deciding how much additional verification you need.

When should I avoid the quick fix for EACCES: permission denied, mkdir '/tmp/claude-code-' — --settings writes cache to shared /tmp/?

For "Claude Code --settings EACCES permission denied on shared macOS when two user accounts share a Mac", avoid applying "Compare the failing environment with a known working setup, then change one configuration value at a time." when the error text differs, the affected version or provider is different, or the change would touch credentials, billing, DNS, production deploy settings, or irreversible data.

What should I collect before debugging EACCES: permission denied, mkdir '/tmp/claude-code-' — --settings writes cache to shared /tmp/?

For "Claude Code --settings EACCES permission denied on shared macOS when two user accounts share a Mac", collect the failing Claude Code command or request, non-secret configuration, versions, timestamps, request IDs when available, and the smallest reproduction that still triggers the signature.