False positive warning about PATH installation when using shell alias

Environment

• [x] Anthropic API
• [ ] Other: Local installation

Claude CLI version: 1.0.38

Operating System: macOS (Darwin 23.6.0)

Terminal: zsh

Bug Description
Claude Code displays a false positive warning about the local installation not being accessible via PATH, even when the alias is properly configured and functional.

Steps to Reproduce

1. Install Claude Code locally using the installer
2. Configure shell alias as instructed: alias claude="/Users/username/.claude/local/claude"
3. Restart shell or source configuration file
4. Run claude update command - it works correctly
5. Observe warning message displayed

Expected Behavior
No warning should be displayed when the alias is properly configured and the claude command is accessible.

Actual Behavior
The following warning appears:

Warning: Local installation not accessible via PATH
Fix: Alias already configured but not active. Restart shell or run: source /Users/mleveck/.zshrc

However, running which claude confirms the alias is active:

claude: aliased to /Users/mleveck/.claude/local/claude

Additional Context
The installation checker appears to only verify the binary exists in standard PATH locations and doesn't account for shell aliases. This creates confusion since the suggested fix (restarting shell/sourcing config) has already been completed and the alias is functional.

The warning is purely cosmetic - Claude Code works correctly despite the message.