pub fn loopback_handshake(
base_url: &str,
options: HandshakeOptions,
) -> Result<PendingHandshake>Expand description
Bind the loopback listener and compute the platform sign-in URL.
This is sync because binding a std::net::TcpListener is sync — there’s
no .await to be had. The async work (waiting for the browser
redirect) lives on PendingHandshake::wait.