Claude.app: "in-folder" session start fails on macOS — git checkout --end-of-options not supported by Apple's bundled git 2.39.5

Summary

When starting a new session in Claude.app on macOS and selecting a source branch without enabling "use worktree", the session start fails immediately with:

Failed to switch to "<branch>" in <path>: /usr/bin/git exited with code 1: error: pathspec '--end-of-options' did not match any file(s) known to git error: pathspec '<branch>' did not match any file(s) known to git

The branch exists, the working tree is clean, and the same branch switches successfully via git switch <branch> on the same /usr/bin/git.

Root cause

The desktop app invokes git checkout --end-of-options <branch> via the hardcoded /usr/bin/git. Apple's bundled git (2.39.5, Apple Git-154) accepts --end-of-options on git switch but not on git checkout — it falls through and treats both --end-of-options and the branch name as pathspecs.

In the bundled main process (/Applications/Claude.app/Contents/Resources/app.asar, .vite/build/index.js):

await yr(["checkout", "--end-of-options", i.sourceBranch], i.cwd, 3e4)
// ...
throw new Error(`Failed to switch to "${i.sourceBranch}" in ${i.cwd}: ${h}`)

/usr/bin/git is hardcoded earlier in the same bundle.

Reproduction

1. macOS with stock Apple git (/usr/bin/git --version → git version 2.39.5 (Apple Git-154)).
2. In Claude.app, start a new session in a repo where the current branch is not the branch you want.
3. Specify a sourceBranch (e.g. dev).
4. Leave "use worktree" disabled.
5. Working tree is clean, target branch exists locally.

Result: session start fails with the error above.

Confirmation from terminal:

• /usr/bin/git checkout --end-of-options dev → fails identically
• /usr/bin/git switch --end-of-options dev → succeeds
• /usr/bin/git checkout dev (no flag) → succeeds

Installing a newer git via Homebrew doesn't help, because the app uses the hardcoded /usr/bin/git, which on macOS is the Apple binary tied to Xcode/CLT and can't be replaced (SIP).

Suggested fix

Either:

1. Replace ["checkout", "--end-of-options", branch] with ["switch", "--end-of-options", branch] — semantically what's intended, and --end-of-options is honoured by switch on Apple's git.
2. Drop --end-of-options for the checkout form (then re-validate the branch name some other way to keep the safety guarantee).
3. Resolve git via PATH instead of hardcoding /usr/bin/git, so users on a newer git aren't stuck with this.

Option 1 looks cleanest.

Environment

• Claude.app version: 1.8555.2
• macOS: Darwin 23.6.0
• Architecture: arm64 (Apple Silicon)
• /usr/bin/git --version: 2.39.5 (Apple Git-154)
• xcode-select -p: /Applications/Xcode.app/Contents/Developer