Server error: 500 returned by Guzzle

[mbrodala]

The notification to Slack doesn't seem to work. After creating a Incoming WebHook (which is not mentioned anywhere BTW) and adding its Webhook URL as url in .rocketeer/plugins/rocketeers/rocketeer-slack/config.php all I get is the following error:

  [GuzzleHttp\Exception\ServerException]
  Server error: 500

Debugging the Guzzle request by adding a ['debug' => true] to the Guzzle instantiation in Maknz\Slack\Client yields the following details:

* Hostname was NOT found in DNS cache
*   Trying 54.88.21.37...
* Connected to hooks.slack.com (54.88.21.37) port 443 (#0)
* successfully set certificate verify locations:
*   CAfile: none
  CApath: /etc/ssl/certs
* SSL connection using ECDHE-RSA-AES128-GCM-SHA256
* Server certificate:
*        subject: C=US; ST=California; L=San Francisco; O=Slack Technologies, Inc; CN=*.slack.com
*        start date: 2015-01-26 00:00:00 GMT
*        expire date: 2017-02-18 23:59:59 GMT
*        subjectAltName: hooks.slack.com matched
*        issuer: C=US; O=GeoTrust Inc.; CN=GeoTrust SSL CA - G3
*        SSL certificate verify ok.
> POST /services/xxx/yyy/zzz HTTP/1.1
User-Agent: GuzzleHttp/6.0.2 curl/7.35.0 PHP/5.5.9-1ubuntu4.11
Host: hooks.slack.com
Content-Length: 129

* upload completely sent off: 129 out of 129 bytes
< HTTP/1.1 500 Server Error
< Access-Control-Allow-Origin: *
< Content-Type: text/html
< Date: Fri, 21 Aug 2015 12:53:21 GMT
* Server Apache is not blacklisted
< Server: Apache
< Strict-Transport-Security: max-age=31536000; includeSubDomains; preload
< X-Frame-Options: SAMEORIGIN
< Content-Length: 17
< Connection: keep-alive
<
* Connection #0 to host hooks.slack.com left intact

The mentioned config.php currently looks like this:

<?php

return [
  'url' => 'https://hooks.slack.com/services/xxx/yyy/zzz',
  'username' => null,
  'room' => null,
];

Any idea what's wrong? Performing a manual request via curl as suggested in the Slack integrations example works fine and the message is properly posted to the channel.

[IlyaPokamestov]

I have this issue too, any progress with it?

[mbrodala]

No, haven't looked into this recently. Since we get notifications from our CI (Shippable) anyways, this is not important anymore. ;-)