'string indices must be integers, not unicode'

[adrien-blookup]

Hi,
I'm trying to use celery-redis-sentinel in my django project, but I always get a :

DecodeError at /fr/
('string indices must be integers, not unicode', <function unpickle_backend at 0x7f4c62dac938>, (<class 'celery_redis_sentinel.backend.RedisSentinelBackend'>, ('redis-sentinel://localhost:7000',), {'expires': 86400}))

I have the following setup :

• 5 redis-servers (1 master and 4 slaves) on 127.0.01:7000-7005
• 4 sentinels on 127.0.0.1:9000-9003
• Celery broker is rabbitmq 3.6.9
• Celery backend is redis 4.0.1

class CeleryConfig:

    CELERY_RESULT_BACKEND = 'redis-sentinel://localhost:9000'
    CELERY_RESULT_BACKEND_TRANSPORT_OPTIONS = {
        'sentinels': [('127.0.0.1', 9000),
                      ('127.0.0.1', 9001),
                      ('127.0.0.1', 9002)],
        'service_name': 'blookup',
        'socket_timeout': 0.1,
    }

celery_redis_sentinel.register()
celery_app = Celery('myapp', backend='redis-sentinel://127.0.0.1:9000')

The error seems to be on backend.py@35 :

 self.sentinels = self.transport_options['sentinels']

self.transport_options value is 'redis-sentinel://localhost:7000' instead of a dict.