Kivent Core compilation

[crigaut]

I tried to install kivent following the instructions and the trick cited in #243 .
I got the following error:

 Error compiling Cython file:
 ------------------------------------------------------------
 ...
 from kivy._event cimport EventDispatcher
 
 cdef class CWidget(EventDispatcher):
     cdef object _context
     cdef object canvas
     cdef object _proxy_ref
                ^
 ------------------------------------------------------------
 
 kivent_core/uix/cwidget.pxd:6:16: '_proxy_ref' redeclared 
 
 Error compiling Cython file:
 ------------------------------------------------------------
 ...
 from kivy._event cimport EventDispatcher
 
 cdef class CWidget(EventDispatcher):
     cdef object _context
     cdef object canvas
     cdef object _proxy_ref
         ^
 ------------------------------------------------------------
 
 kivent_core/uix/cwidget.pxd:6:9: Compiler crash in AnalyseDeclarationsTransform
 
 File 'ModuleNode.py', line 124, in analyse_declarations: ModuleNode(cwidget.pxd:1:0,
     full_module_name = 'kivent_core.uix.cwidget',
     is_pxd = True)
 File 'Nodes.py', line 431, in analyse_declarations: StatListNode(cwidget.pxd:1:0)
 File 'Nodes.py', line 4791, in analyse_declarations: CClassDefNode(cwidget.pxd:3:5,
     as_name = 'CWidget',
     class_name = 'CWidget',
     in_pxd = True,
     module_name = '',
     visibility = 'private')
 File 'Nodes.py', line 431, in analyse_declarations: StatListNode(cwidget.pxd:4:4)
 File 'Nodes.py', line 1390, in analyse_declarations: CVarDefNode(cwidget.pxd:6:9,
     in_pxd = True,
     modifiers = [...]/0,
     visibility = 'private')
 
 Compiler crash traceback from this point on:
   File "/home/clement/Documents/Personnel/github/kivy/venv/lib/python3.6/site-packages/Cython/Compiler/Nodes.py", line 1390, in analyse_declarations
     api=self.api, is_cdef=1)
   File "/home/clement/Documents/Personnel/github/kivy/venv/lib/python3.6/site-packages/Cython/Compiler/Symtab.py", line 2131, in declare_var
     entry = self.declare(name, cname, type, pos, visibility)
   File "/home/clement/Documents/Personnel/github/kivy/venv/lib/python3.6/site-packages/Cython/Compiler/Symtab.py", line 476, in declare
     entries[name].already_declared_here()
   File "/home/clement/Documents/Personnel/github/kivy/venv/lib/python3.6/site-packages/Cython/Compiler/Symtab.py", line 223, in already_declared_here
     error(self.pos, "Previous declaration is here")
   File "/home/clement/Documents/Personnel/github/kivy/venv/lib/python3.6/site-packages/Cython/Compiler/Errors.py", line 178, in error
     raise InternalError(message)
 InternalError: Internal compiler error: Previous declaration is here
 Traceback (most recent call last):
   File "setup.py", line 184, in <module>
     extensions, core_modules)
   File "setup.py", line 164, in build_extensions_for_modules_cython
     return cythonize(ext_list)
   File "/home/clement/Documents/Personnel/github/kivy/venv/lib/python3.6/site-packages/Cython/Build/Dependencies.py", line 1097, in cythonize
     cythonize_one(*args)
   File "/home/clement/Documents/Personnel/github/kivy/venv/lib/python3.6/site-packages/Cython/Build/Dependencies.py", line 1220, in cythonize_one
     raise CompileError(None, pyx_file)
 Cython.Compiler.Errors.CompileError: kivent_core/entity.pyx

Is there something to fix this?