How to fix a bug in Kivy?

Question

Python

Made a simple application that just creates a button. Launched. Got the following error:

[INFO              ] [Logger      ] Record log in /home/nafanya/.kivy/logs/kivy_18-05-22_11.txt
[INFO              ] [Kivy        ] v1.9.1
[INFO              ] [Python      ] v3.6.5 (default, Apr  1 2018, 05:46:30) 
[GCC 7.3.0]
[INFO              ] [Factory     ] 179 symbols loaded
[INFO              ] [Image       ] Providers: img_tex, img_dds, img_gif, img_sdl2, img_pil (img_ffpyplayer ignored)
[INFO              ] [Text        ] Provider: sdl2
[INFO              ] [OSC         ] using <multiprocessing> for socket
[INFO              ] [Window      ] Provider: sdl2(['window_egl_rpi'] ignored)
[CRITICAL          ] [Window      ] Unable to find any valuable Window provider at all!
egl_rpi - ImportError: cannot import name 'bcm'
  File "/usr/lib/python3/dist-packages/kivy/core/__init__.py", line 59, in core_select_lib
    fromlist=[modulename], level=0)
  File "/usr/lib/python3/dist-packages/kivy/core/window/window_egl_rpi.py", line 12, in <module>
    from kivy.lib.vidcore_lite import bcm, egl

sdl2 - TypeError: expected bytes, str found
  File "/usr/lib/python3/dist-packages/kivy/core/__init__.py", line 67, in core_select_lib
    cls = cls()
  File "/usr/lib/python3/dist-packages/kivy/core/window/window_sdl2.py", line 138, in __init__
    super(WindowSDL, self).__init__()
  File "/usr/lib/python3/dist-packages/kivy/core/window/__init__.py", line 722, in __init__
    self.create_window()
  File "/usr/lib/python3/dist-packages/kivy/core/window/window_sdl2.py", line 237, in create_window
    self.fullscreen, resizable, state)
  File "kivy/core/window/_window_sdl2.pyx", line 94, in kivy.core.window._window_sdl2._WindowSDL2Storage.setup_window (kivy/core/window/_window_sdl2.c:2204)

x11 - ModuleNotFoundError: No module named 'kivy.core.window.window_x11'
  File "/usr/lib/python3/dist-packages/kivy/core/__init__.py", line 59, in core_select_lib
    fromlist=[modulename], level=0)

[CRITICAL          ] [App         ] Unable to get a Window, abort.
 Exception ignored in: 'kivy.properties.dpi2px'
 Traceback (most recent call last):
   File "/usr/lib/python3/dist-packages/kivy/utils.py", line 513, in __get__
     retval = self.func(inst)
   File "/usr/lib/python3/dist-packages/kivy/metrics.py", line 175, in dpi
     EventLoop.ensure_window()
   File "/usr/lib/python3/dist-packages/kivy/base.py", line 126, in ensure_window
     sys.exit(1)
 SystemExit: 1
[CRITICAL          ] [App         ] Unable to get a Window, abort.

If it is very important, here is the code of the program:

import kivy
from kivy.app import App
from kivy.uix.button import Button

class CalcApp(App):
    def build(self):
        return Button(text='Hello,world!')


if __name__=='__main__':
    CalcApp().run()

Answer 1

sudo apt-get remove python3-kivy
sudo pip3 install kivy