Structured error returned by Rover functions.

Rover.fetch/2 and browser commands return {:error, %Rover.Error{}} on failure — never raise. Pattern match on :reason to dispatch recovery:

case Rover.fetch(url) do
  {:ok, result} ->
    handle(result)

  {:error, %Rover.Error{reason: :timeout}} ->
    Logger.warning("slow page: #{url}")
    :skip

  {:error, %Rover.Error{reason: :proxy}} ->
    retry_direct(url)
end

Reason atoms

• :timeout — page load exceeded the configured timeout.
• :navigation — URL could not be reached (DNS, TLS, connection reset).
• :selector_not_found — a selector expected by the operation did not match.
• :selector_timeout — wait_for selector did not appear in time.
• :evaluation — JavaScript evaluation threw.
• :proxy — proxy connection failed.
• :invalid_argument — malformed argument (bad URL, unknown option, etc.).
• :runtime — internal runtime error (NIF / subprocess / wire protocol).
• :shutdown — runtime is shutting down and refused the request.
• :port_died — the runtime subprocess exited unexpectedly.