[BUG] ENOSPC: no space left on device error during workflow, despite available disk space

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?

ENOSPC: no space left on device error occurs when attempting to write or append files using Claude Code in the middle of a workflow. The system is not actually out of disk space, so the error appears to be misleading. This prevents successful file creation or modification and disrupts ongoing tasks.

What Should Happen?

Files should be created, written, or appended successfully unless the system disk is truly full. If disk space is exhausted, the error should be handled gracefully and the user should be informed clearly.

Error Messages/Logs

ENOSPC: no space left on device, write
      fd: 10,
 syscall: "write",
   errno: -28,
    code: "ENOSPC"

      at appendFileSync (/$bunfs/root/claude:12:882)
      at o (/$bunfs/root/claude:14:103)
      at iM (/$bunfs/root/claude:3455:833)
      at fFW (/$bunfs/root/claude:3432:14706)
      at $2 (/$bunfs/root/claude:3446:370)
      at a69 (/$bunfs/root/claude:277:627)
      at aR (/$bunfs/root/claude:277:491)
      at pu0 (/$bunfs/root/claude:2655:154)
      at processTicksAndRejections (7:39)

Steps to Reproduce

1. Run Claude Code and initiate a workflow that involves file writing or appending operations.
2. The error output 'ENOSPC: no space left on device' appears during the flow, not during install.
3. System disk space is confirmed to be available, so the error is not due to actual disk exhaustion.
4. Review stack trace for failing operation.

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

2.0.13

Claude Code Version

2.0.14

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

iTerm2

Additional Information

This issue is not related to startup, install, or file watcher limits as described in existing issues #7624, #7278, and #8575. It occurs in the middle of a workflow and on a system with available disk space. Please investigate whether the error is caused by a misinterpretation of disk usage or another underlying problem. Regression confirmed: did not occur in v2.0.13, only in v2.0.14.