ImportWarning: can't resolve package from __spec__ or __package__, falling back on __name__ and __path__

[gjcarneiro]

root@41ed389453bb:/code# PYTHONWARNINGS=default python
Python 3.7.1 (default, Oct 24 2018, 22:38:59) 
[GCC 6.3.0 20170516] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import capnpy
/usr/local/lib/python3.7/importlib/_bootstrap.py:219: ImportWarning: can't resolve package from __spec__ or __package__, falling back on __name__ and __path__
  return f(*args, **kwds)
/usr/local/lib/python3.7/site-packages/_pytest/assertion/rewrite.py:8: DeprecationWarning: the imp module is deprecated in favour of importlib; see the module's documentation for alternative uses
  import imp
>>> 

root@41ed389453bb:/code# python -Werr
Python 3.7.1 (default, Oct 24 2018, 22:38:59) 
[GCC 6.3.0 20170516] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import capnpy
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python3.7/site-packages/capnpy/__init__.py", line 4, in <module>
    from capnpy.compiler.compiler import DynamicCompiler
  File "/usr/local/lib/python3.7/site-packages/capnpy/compiler/compiler.py", line 11, in <module>
    from capnpy import schema
  File "/usr/local/lib/python3.7/site-packages/capnpy/schema.py", line 6, in <module>
    from capnpy.struct_ import Struct as _Struct
  File "capnpy/struct_.py", line 1, in init capnpy.struct_
  File "capnpy/type.pxd", line 1, in init capnpy.blob
  File "capnpy/type.py", line 1, in init capnpy.type
ImportWarning: can't resolve package from __spec__ or __package__, falling back on __name__ and __path__