[BUG] extraKnownMarketplaces directory source resolves against main repo root instead of worktree root

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 running Claude Code from a manually created git worktree, the extraKnownMarketplaces setting with a relative "path" resolves against the main repository root instead of the current worktree root. This causes local plugin marketplaces to fail to load.

The path resolves from the main repo root: Marketplace file not found at /path/to/main-repo/.claude-plugins/.claude-plugin/marketplace.json

What Should Happen?

The relative path .claude-plugins resolves from the worktree root, loading the marketplace at <worktree>/.claude-plugins/.claude-plugin/marketplace.json.

Error Messages/Logs

❯ test-local (project)
      Marketplace file not found at /private/tmp/worktree-plugin-bug/main-repo/.claude-plugins/.claude-plugin/marketplace.json

   ✘ hello-plugin @ test-local (project)
      Plugin "hello-plugin" not found in marketplace "test-local"
      Plugin may not exist in marketplace "test-local"

Steps to Reproduce

1. Create a test repo and a worktree:

mkdir /tmp/worktree-plugin-bug && cd /tmp/worktree-plugin-bug
git init main-repo && cd main-repo
git commit --allow-empty -m "init"
git worktree add ../worktree -b test-branch
cd ../worktree

1. Create a local marketplace with one plugin

mkdir -p .claude-plugins/.claude-plugin
mkdir -p .claude-plugins/hello-plugin/.claude-plugin

cat > .claude-plugins/.claude-plugin/marketplace.json << 'EOF'
{
  "name": "test-local",
  "owner": { "name": "Test", "email": "test@example.com" },
  "metadata": { "description": "Test local marketplace" },
  "plugins": [
    { "name": "hello-plugin", "source": "./hello-plugin" }
  ]
}
EOF

cat > .claude-plugins/hello-plugin/.claude-plugin/plugin.json << 'EOF'
{
  "name": "hello-plugin",
  "version": "1.0.0",
  "description": "Test plugin"
}
EOF

1. Configure Claude to use it

mkdir -p .claude
cat > .claude/settings.json << 'EOF'
{
  "extraKnownMarketplaces": {
    "test-local": {
      "source": {
        "source": "directory",
        "path": ".claude-plugins"
      }
    }
  },
  "enabledPlugins": {
    "hello-plugin@test-local": true
  }
}
EOF

1. Launch claude from the worktree

claude /plugin and tab across to errors

Symlinking the marketplace into main-repo makes the plugin load successfully.

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.112 (Claude Code)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

VS Code integrated terminal

Additional Information

_No response_