[BUG] Sandbox blocks file access on removable USB volumes for PATH-resolved binaries, /usr/bin/ equivalents work

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?

Commands run through Claude Code's sandbox cannot access files on a removable USB volume (ExFAT, /Volumes/Extreme SSD/), returning "Operation not permitted." This only affects binaries resolved through PATH (e.g. git via ~/.nvm/). System binaries at /usr/bin/git, /bin/cat, /bin/ls work fine on the same paths.

macOS kernel log confirms: (Sandbox) System Policy: git(43270) deny(1) file-read-data /Volumes/Extreme SSD/Home
(Sandbox) System Policy: cat(43508) deny(1) file-read-data /Volumes/Extreme SSD/Home/portfolio/.git/HEAD

Terminal has Full Disk Access enabled. The volume is mounted and accessible outside the sandbox. This worked in previous versions and broke mid-session on 2.1.98.

Platform: macOS Darwin 25.5.0
Volume: ExFAT over USB
Claude Code: 2.1.98

What Should Happen?

Sandbox should allow file read/write access to mounted removable volumes, consistent with the behavior of system binaries and previous Claude Code versions.

Error Messages/Logs

2026-04-09 15:42:10.768 E kernel[0:f180c] (Sandbox) System Policy: git(43270) deny(1) file-read-data /Volumes/Extreme SSD/Home                       
  2026-04-09 15:42:42.009 E kernel[0:f1a55] (Sandbox) System Policy: git(43388) deny(1) file-read-data /Volumes/Extreme SSD/Home/portfolio/.git/HEAD   
  2026-04-09 15:42:50.648 E kernel[0:f1b7c] (Sandbox) System Policy: cat(43508) deny(1) file-read-data /Volumes/Extreme SSD/Home/portfolio/.git/HEAD   
  2026-04-09 15:43:53.904 E kernel[0:f1e1e] (Sandbox) System Policy: cat(43570) deny(1) file-read-data /Volumes/Extreme SSD/Home/portfolio/.git/config 
  2026-04-09 15:44:00.274 E kernel[0:f1f6b] (Sandbox) System Policy: cat(43682) deny(1) file-read-data /Volumes/Extreme SSD/Home/portfolio/README.md   
  2026-04-09 15:44:04.688 E kernel[0:f1fee] (Sandbox) System Policy: ls(43748) deny(1) file-read-data /Volumes/Extreme SSD/Home/portfolio

Steps to Reproduce

1. Connect an ExFAT USB drive (e.g. /Volumes/Extreme SSD/)
2. Open Claude Code from Terminal (which has Full Disk Access)
3. Run any command targeting the volume: git -C "/Volumes/Extreme SSD/Home/project" status
4. Observe "Operation not permitted"
5. Run the same command with the system binary: /usr/bin/git -C "/Volumes/Extreme SSD/Home/project" status
6. Observe it works fine

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.98 (Claude Code)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

Workaround: using full system binary paths (/usr/bin/git, /bin/cat, /bin/ls) instead of PATH-resolved binaries bypasses the issue.

Volume details: ExFAT filesystem, USB-connected SSD, mounted at /Volumes/Extreme SSD/
Node installed via nvm at ~/.nvm/versions/node/v24.8.0/
git resolves to nvm path, not /usr/bin/git

This has been a working setup for nearly a year. Seems to have broke within the last few days.