[BUG] Worktree isolation fails with "Background full checkout failed: git-crypt-locked" in git-crypt repos

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?

When starting a new Claude Code Desktop session with worktree isolation enabled, the session creation fails with:

Background full checkout failed: git-crypt-locked

This happens in any repository that uses git-crypt to encrypt files via .gitattributes filter rules, e.g.:

conf/**             filter=git-crypt diff=git-crypt
certificates/** filter=git-crypt diff=git-crypt

Steps to reproduce:

1. Clone a repository that uses git-crypt with files matching .gitattributes filter rules
2. Open Claude Code Desktop and start a new session with "worktree" isolation checked
3. Observe the error

Expected behavior: The worktree is created successfully. Encrypted files remain encrypted (locked) in the new worktree — that is acceptable.

Actual behavior: git worktree add fails because git invokes the git-crypt smudge filter during checkout, which exits non-zero when the repo is locked, and since filter.git-crypt.required=true by default, the entire checkout aborts.

Additional context:

• Running git-crypt unlock before creating the session does not resolve the issue.
• Other AI coding tools (e.g. Codex) handle this without error, likely by using --no-checkout or by passing -c filter.git-crypt.required=false to git worktree add.

Suggested fix:

When creating a worktree, pass the following git config overrides to bypass the smudge filter:

git \
  -c filter.git-crypt.smudge=cat \
  -c filter.git-crypt.clean=cat \
  -c filter.git-crypt.required=false \
  worktree add <path> <branch>

This allows the checkout to succeed with encrypted files remaining as encrypted bytes — which is the correct behavior for a locked worktree.

Environment:

• OS: macOS 15.3
• git-crypt: 0.7.0
• git: 2.47.0

What Should Happen?

A new worktree should be created.

Error Messages/Logs

Background full checkout failed: git-crypt-locked

Steps to Reproduce

For me, this happens (all the time) when starting a new session as a worktree in a repo that has git-crypt configured after upgrading to the latest version of claude code desktop (Claude 1.7196.0 (2dbd78) 2026-05-12T05:34:40.000Z).

However, colleagues of mine have ran into this on older versions. Some have given up on using worktrees altogether while for others it has magically started working again after a while.

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

Claude 1.7196.0 (2dbd78) 2026-05-12T05:34:40.000Z

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Warp

Additional Information

I'm using claude code desktop