jedi-vim: sys.executable might be Vim itself with embedded Python (UnpicklingError)

(sorry for miss spellings, I’m french and I’ll try my best to explain my issue)

Issue

When I try to <c-space> or when jedi-vim want to help me, a new window of gvim pop-up with main.py oppened from jedi’s file instead of the list of propositions and sometimes, when I go back to the previews window, gvim stop working…

Steps to reproduce

here is my _vimrc ::

source $VIMRUNTIME/vimrc_example.vim

let python_highlight_all=1
syntax on

"Enable folding + space to fold
set foldmethod=indent
set foldlevel=99
nnoremap <space> za

set diffexpr=MyDiff()
function MyDiff()
  let opt = '-a --binary '
  if &diffopt =~ 'icase' | let opt = opt . '-i ' | endif
  if &diffopt =~ 'iwhite' | let opt = opt . '-b ' | endif
  let arg1 = v:fname_in
  if arg1 =~ ' ' | let arg1 = '"' . arg1 . '"' | endif
  let arg1 = substitute(arg1, '!', '\!', 'g')
  let arg2 = v:fname_new
  if arg2 =~ ' ' | let arg2 = '"' . arg2 . '"' | endif
  let arg2 = substitute(arg2, '!', '\!', 'g')
  let arg3 = v:fname_out
  if arg3 =~ ' ' | let arg3 = '"' . arg3 . '"' | endif
  let arg3 = substitute(arg3, '!', '\!', 'g')
  if $VIMRUNTIME =~ ' '
    if &sh =~ '\<cmd'
      if empty(&shellxquote)
        let l:shxq_sav = ''
        set shellxquote&
      endif
      let cmd = '"' . $VIMRUNTIME . '\diff"'
    else
      let cmd = substitute($VIMRUNTIME, ' ', '" ', '') . '\diff"'
    endif
  else
    let cmd = $VIMRUNTIME . '\diff'
  endif
  let cmd = substitute(cmd, '!', '\!', 'g')
  silent execute '!' . cmd . ' ' . opt . arg1 . ' ' . arg2 . ' > ' . arg3
  if exists('l:shxq_sav')
    let &shellxquote=l:shxq_sav
  endif
endfunction

set nu
set guifont=Courier_new:h11
set encoding=utf-8
set nocompatible
color desert

filetype off
set rtp+=%USERPROFILE%/vim/bundle/Vundle.vim/
call vundle#begin('%USERPROFILE%/vim/bundle/')

Plugin 'vundleVim/Vundle.vim'
Plugin 'scrooloose/nerdtree'
Plugin 'itchyny/lightline.vim'
Plugin 'mattn/emmet-vim'
Plugin 'Xuyuanp/nerdtree-git-plugin'
Plugin 'altercation/vim-colors-solarized'
Plugin 'jiangmiao/auto-pairs'
Plugin 'kien/rainbow_parentheses.vim'
Plugin 'vim-syntastic/syntastic'
Plugin 'nvie/vim-flake8'
Plugin 'tpope/vim-dispatch'
Plugin 'https://github.com/StanAngeloff/php.vim.git'
Plugin 'joonty/vim-phpqa'
Plugin 'davidhalter/jedi-vim'

call vundle#end()
filetype plugin indent on

"if has('gui_running')
"	set background=dark
"	colorscheme solarized
"else
"	colorscheme zenburn
"endif

filetype plugin on
set omnifunc=syntaxcomplete#Complete

Output of “:verbose JediDebugInfo”

when I do this command, the same windows apear with

import sys
import os


def _get_paths():
    # Get the path to jedi.
    _d = os.path.dirname
    _jedi_path = _d(_d(_d(_d(_d(__file__)))))
    _parso_path = sys.argv[1]
    # The paths are the directory that jedi and parso lie in.
    return {'jedi': _jedi_path, 'parso': _parso_path}


# Remove the first entry, because it's simply a directory entry that equals
# this directory.
del sys.path[0]

if sys.version_info > (3, 4):
    from importlib.machinery import PathFinder

    class _ExactImporter(object):
        def __init__(self, path_dct):
            self._path_dct = path_dct

        def find_module(self, fullname, path=None):
            if path is None and fullname in self._path_dct:
                p = self._path_dct[fullname]
                loader = PathFinder.find_module(fullname, path=[p])
                return loader
            return None

    # Try to import jedi/parso.
    sys.meta_path.insert(0, _ExactImporter(_get_paths()))
    from jedi.evaluate.compiled import subprocess  # NOQA
    sys.meta_path.pop(0)
else:
    import imp

    def load(name):
        paths = list(_get_paths().values())
        fp, pathname, description = imp.find_module(name, paths)
        return imp.load_module(name, fp, pathname, description)

    load('parso')
    load('jedi')
    from jedi.evaluate.compiled import subprocess  # NOQA

# Retrieve the pickle protocol.
pickle_protocol = int(sys.argv[2])
# And finally start the client.
subprocess.Listener(pickle_protocol).listen()