autocomplete - PyCharm: no autocompletion of Cython package -

scenario:

• own package, build cython
• python 3.5 interpreter finds package, executing code works
• python help() works expected (methods of classes etc shown, method signatures missing)

in pycharm set correct interpreter , package shows in package list (settings -> project .. -> project interpreter). package shows in list of interpreter paths.

but: autocompletion , documentation not work properly package. classes seem found, long included in __all__ of __init__.py , stringdoc top module shown, that's it.

i used "invalidate caches / restart" several times. ideas how autocompletion work?

update: noticed pycharm creates stubs (that seem correct) not use them auto completion or help.