I'm trying to load a CSV file, from Google Cloud Storage, into an empty Google Big Query table, through a GoogleCloudStorageToBigQueryOperator task.

```
t8 = GoogleCloudStorageToBigQueryOperator(
    task_id='gcs_send_dim_report',
    bucket='report',
    source_objects=[
        'gs://report/test-dim-report/dim_report_{{ ds_nodash }}.csv'
    ],
    schema_fields=['filename_pdf','filename_png', 'week_date', 'code'],
    skip_leading_rows=1,
    source_format = 'CSV',
    create_disposition='CREATE_IF_NEEDED',
    write_disposition='WRITE_TRUNCATE',
    destination_project_dataset_table='xxxx-yyyy:report.test_dim_report_{{ ds_nodash }}',
    dag=dag
)

```

The table to be loaded already has schema defined in Big Query, even so, to face this error, I added the parameter `schema_fields` with the columns of the CSV that I am using. Looking at the task log, I first encounter the following dependency errors:

```
from google.appengine.api import memcache
[2018-06-22 05:58:49,650] {base_task_runner.py:98} INFO - Subtask: ImportError: No module named 'google.appengine'
[2018-06-22 05:58:49,650] {base_task_runner.py:98} INFO - Subtask: 
[2018-06-22 05:58:49,651] {base_task_runner.py:98} INFO - Subtask: During handling of the above exception, another exception occurred:
[2018-06-22 05:58:49,651] {base_task_runner.py:98} INFO - Subtask: 
[2018-06-22 05:58:49,651] {base_task_runner.py:98} INFO - Subtask: Traceback (most recent call last):
[2018-06-22 05:58:49,652] {base_task_runner.py:98} INFO - Subtask:   File "/usr/local/lib/python3.5/dist-packages/googleapiclient/discovery_cache/file_cache.py", line 33, in <module>
[2018-06-22 05:58:49,652] {base_task_runner.py:98} INFO - Subtask:     from oauth2client.contrib.locked_file import LockedFile
[2018-06-22 05:58:49,652] {base_task_runner.py:98} INFO - Subtask: ImportError: No module named 'oauth2client.contrib.locked_file'

```

At the end of the log, the final error is displayed:

```
Exception: BigQuery job failed. Final error was: {'reason': 'invalid', 'message': 'Empty schema specified for the load job. Please specify a schema that describes the data being loaded.'}.

```

I'm looking for some workaroud for that error, in order to successfully load my CSV file into Google Big Query