初始化数据库报错pony.orm.core.TransactionError: db_session is required when working with the database

test@server:~/collipa-master$ python setup.py --init
Traceback (most recent call last):
File "setup.py", line 77, in
main(sys.argv[1:])
File "setup.py", line 38, in main
if not Node.get(id=1):
File "/usr/local/lib/python2.7/dist-packages/pony/utils.py", line 81, in new_func
return old_func(_args, *_kwargs)
File "/usr/local/lib/python2.7/dist-packages/pony/orm/core.py", line 2240, in get
objects = entity._find_(1, kwargs) # can throw MultipleObjectsFoundError
File "/usr/local/lib/python2.7/dist-packages/pony/orm/core.py", line 2280, in _find_
objects = entity._find_in_cache_(pkval, avdict)
File "/usr/local/lib/python2.7/dist-packages/pony/orm/core.py", line 2288, in _find_in_cache_
cache = entity._get_cache_()
File "/usr/local/lib/python2.7/dist-packages/pony/orm/core.py", line 2553, in _get_cache_
return database._get_cache()
File "/usr/local/lib/python2.7/dist-packages/pony/orm/core.py", line 345, in _get_cache
): throw(TransactionError, 'db_session is required when working with the database')
File "/usr/local/lib/python2.7/dist-packages/pony/utils.py", line 108, in throw
raise exc
pony.orm.core.TransactionError: db_session is required when working with the database
test@server:~/collipa-master$