ValueError: No JSON object could be decoded

[dsafanyuk]

Not sure if this repo is still being supported.

But im getting this after i tag the bot:

resource script '/opt/resource/check []' failed: exit status 1

stderr:
Traceback (most recent call last):
  File "/opt/resource/check_op.py", line 99, in <module>
    main()
  File "/opt/resource/check_op.py", line 91, in main
    slack_client = Check(**payload.args)
  File "/opt/resource/check_op.py", line 15, in __init__
    Base.__init__(self, **kwargs)
  File "/opt/resource/base.py", line 20, in __init__
    self.users = self._call_api("users.list", presence=0)
  File "/opt/resource/base.py", line 33, in _call_api
    api_response = self.slack_client.api_call(method, **kwargs)
  File "/usr/lib/python2.7/site-packages/slackclient/client.py", line 85, in api_call
    result = json.loads(self.server.api_call(method, timeout=timeout, **kwargs))
  File "/usr/lib/python2.7/json/__init__.py", line 339, in loads
    return _default_decoder.decode(s)
  File "/usr/lib/python2.7/json/decoder.py", line 364, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
  File "/usr/lib/python2.7/json/decoder.py", line 382, in raw_decode
    raise ValueError("No JSON object could be decoded")
ValueError: No JSON object could be decoded

pipeline.yml

# Jobs
- name: trigger-release
  serial: true
  public: true
  plan:
    - get: bender
      version: every
      trigger: true
# Resource Types
- name: bender-resource
  type: docker-image
  source:
    repository: quay.io/ahelal/bender
    tag: latest
# Resource
  - name: bender
    type: bender-resource
    source:
      slack_token: <token>
      channel: "slack_test_channel"