[php] Handle Guzzle exception and get HTTP body

None of the above responses are working for error that has no body but still has some describing text. For me, it was SSL certificate problem: unable to get local issuer certificate error. So I looked right into the code, because doc does't really say much, and did this (in Guzzle 7.1):

try {
    // call here
} catch (\GuzzleHttp\Exception\RequestException $e) {
    if ($e->hasResponse()) {
        $response = $e->getResponse();
        // message is in $response->getReasonPhrase()
    } else {
        $response = $e->getHandlerContext();
        if (isset($response['error'])) {
            // message is in $response['error']
        } else {
            // Unknown error occured!
        }
    }
}