C++ Lamba - error: no matching function for call to

I am trying to pass a lambda as parameter to a function but once I attempt to access a variable inside the lambda which was declared outside, the build fails: error: no matching function for call to 'AWS::subscribe(char [128], mainTask(void*)::<lambda(AWS_IoT_Client*, char*, uint16_t, IoT_Publish_Message_Params*, void*)>)'

I was thinking that the [&] would take care of capturing variables. I also tried [=] as well as [someVar], [&someVar].

I'm using C++11.

char someVar[128];

aws->subscribe(
  topic,
  [&] (AWS_IoT_Client *pClient, char *topicName, uint16_t topicNameLen, IoT_Publish_Message_Params *params, void *pData) {
    char *text = (char *)params->payload;
    sprintf(someVar, "%s", text);
  }
);

From the AWS library:

void AWS::subscribe(const char *topic,
                    pApplicationHandler_t iot_subscribe_callback_handler) {
  m_error =
      ::aws_iot_mqtt_subscribe(&m_client, topic, (uint16_t)std::strlen(topic),
                              QOS1, iot_subscribe_callback_handler, NULL);

}