The current node list is empty.

$form = $crawler->selectButton('Ingresar')->form();
$form->setValues(['rut' => 'admin', 'password' => 'Pascual4900']);
$crawler = $client->submit($form);

<form id="login-form" method="POST" action="/sessions/authenticate">
	<div class="login-container">
		<div class="input" style="cursor:text;" onclick="jQuery('input', this).focus();">
			<h5 style="margin:0">Usuario</h5>
			<input name="rut" type="text" style="font-size:18px;border:0;-webkit-box-shadow:0 0 0;-moz-box-shadow:0 0 0;box-shadow:0 0 0 inset;padding:10px 0 0 0;" placeholder="Escriba su usuario...">
		</div>
		<div class="input" style="cursor:text;" onclick="jQuery('input', this).focus();">
			<h5 style="margin:0">Clave</h5>
			<input name="password" type="password" style="font-size:18px;border:0;-webkit-box-shadow:0 0 0;-moz-box-shadow:0 0 0;box-shadow:0px 0px 0px inset;padding:10px 0 0 0;" placeholder="Escriba su clave...">
		</div>
		<input id="ingresar" onclick="submitForm()" name="ingresar" class="btn btn-success" style="width:390px;-webkit-border-radius:0 !important;-moz-border-radius:0 !important;border-radius:0 !important;text-align:center;font-size:18px;font-weight:bold;color:#fff;padding:20px 0;cursor:pointer;background-image:none;" value="Ingresar">
	</div>
</form>