The claude-code-action's built-in installer uses `curl https://claude.ai/install.sh | bash` which can fail with 403. Due to the pipe, bash exits 0 on empty input, masking the curl failure and leaving the `claude` binary missing. Work around this by installing Claude Code via npm before invoking the action, and passing the executable path via path_to_claude_code_executable. Co-authored-by: Copilot <copilot@github.com>