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

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

1. Confirm the exact error signature matches EACCES: permission denied, mkdir '/tmp/claude-code-' — --settings writes cache to shared /tmp/.
2. Check the Claude Code account, local tool state, and provider configuration involved in the failing workflow.
3. 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

1. Capture the exact error message and the command, editor action, or request that triggered it.
2. Check whether the failure is account/auth, quota/rate, model/provider, local runtime, or deployment configuration.
3. Review the source evidence below and compare it with your environment.
4. Apply one change at a time and rerun the smallest failing action.
5. 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.

Sources checked

• https://github.com/anthropics/claude-code/issues/59041

Evidence note: 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.

Related errors

• Claude Code permission denied macOS
• Claude Code shared environment cache conflict

FAQ

What should I check first?

Start with the exact EACCES: permission denied, mkdir '/tmp/claude-code-' — --settings writes cache to shared /tmp/ text and the smallest action that reproduces it.

Can I ignore this error?

No. Treat it as a failed Claude Code workflow until the root cause is understood.

Is this guaranteed to have one fix?

No. The imported evidence supports the troubleshooting path above, but tool behavior can vary by account, plan, version, provider, and local configuration.

How do I know the fix worked?

Rerun the same command, editor action, or request. The fix is working when that action completes without EACCES: permission denied, mkdir '/tmp/claude-code-' — --settings writes cache to shared /tmp/.