Buster RPi4B unable to find valuable Window provider from Desktop-less console

After logging on the Raspberry Pi 4B to the command line (using raspi-config boot to CLI), cannot execute kivy because of critical error when attempting to use any kivy Window provider: egl_rpi, sdl2, pygame, or x11. This issue lists the attempts and results of each of these Window providers. These providers are listed on the following page:

https://kivy.org/doc/stable/guide/environment.html

KIVY_WINDOW Implementation to use for creating the Window Values: sdl2, pygame, x11, egl_rpi

Versions

• Python: 3.7.3
• OS: Raspbian Buster 4.19
• Kivy: 1.11.1
• Kivy installation method: https://github.com/kivy/kivy/issues/6413

Description

The same test.py program listed below was used to test all of the Window providers listed above. The second line is changed for each test results.

import os
#os.environ['KIVY_WINDOW'] = 'egl_rpi'
from kivy.app import App
from kivy.uix.button import Button

class TestApp(App):
	def build(self):
		return Button(text='Hello World')

TestApp().run()

When no (default) KIVY_WINDOW defined (test.py above), gets the following results:

[DEBUG  ] [Window      ] Provider <egl_rpi> ignored by config
[DEBUG  ] [Window      ] Provider <sdl2> ignored by config
[DEBUG  ] [Window      ] Provider <x11> ignored by config
[CRITICAL] [Window      ] Unable to find any valuable Window provider. 
[CRITICAL] [App         ] Unable to get a Window, abort.

After changing line 2 by removing the # sign, got the following results:

[DEBUG  ] [Window      ] Ignored <egl_rpi> (import error)
[DEBUG  ] [Window      ] Provider <sdl2> ignored by config
[DEBUG  ] [Window      ] Provider <x11> ignored by config
[CRITICAL] [Window      ] Unable to find any valuable Window provider. 
egl_rpi - ImportError: cannot import name 'bcm' from 'kivy.lib.vidcore_lite' (/usr/local/lib/python3.7/dist-packages/kivy/lib/vidcore_lite/__init__.py)
  File "/usr/local/lib/python3.7/dist-packages/kivy/core/__init__.py", line 63, in core_select_lib
    fromlist=[modulename], level=0)
  File "/usr/local/lib/python3.7/dist-packages/kivy/core/window/window_egl_rpi.py", line 12, in <module>
    from kivy.lib.vidcore_lite import bcm, egl
[CRITICAL] [App         ] Unable to get a Window, abort.

After changing line 2 to os.environ['KIVY_WINDOW'] = 'sdl2', got the following results:

[DEBUG  ] [Window      ] Provider <egl_rpi> ignored by config
[INFO   ] [Window      ] Provider: sdl2(['window_egl_rpi'] ignored)
[DEBUG  ] [Window      ] Provider <x11> ignored by config
[CRITICAL] [Window      ] Unable to find any valuable Window provider. Please enable debug logging (e.g. add -d if running from the command line, or change the log level in the config) and re-run your app to identify potential causes
sdl2 - RuntimeError: b'Could not initialize EGL'
  File "/usr/local/lib/python3.7/dist-packages/kivy/core/__init__.py", line 71, in core_select_lib
    cls = cls()
  File "/usr/local/lib/python3.7/dist-packages/kivy/core/window/window_sdl2.py", line 152, in __init__
    super(WindowSDL, self).__init__()
  File "/usr/local/lib/python3.7/dist-packages/kivy/core/window/__init__.py", line 981, in __init__
    self.create_window()
  File "/usr/local/lib/python3.7/dist-packages/kivy/core/window/window_sdl2.py", line 290, in create_window
    self.get_gl_backend_name())
  File "kivy/core/window/_window_sdl2.pyx", line 224, in kivy.core.window._window_sdl2._WindowSDL2Storage.setup_window
  File "kivy/core/window/_window_sdl2.pyx", line 74, in kivy.core.window._window_sdl2._WindowSDL2Storage.die
[CRITICAL] [App         ] Unable to get a Window, abort.

After changing line 2 to os.environ['KIVY_WINDOW'] = 'pygame', got the following results:

[DEBUG  ] [Window      ] Provider <egl_rpi> ignored by config
[DEBUG  ] [Window      ] Provider <sdl2> ignored by config
[DEBUG  ] [Window      ] Provider <x11> ignored by config
[CRITICAL] [Window      ] Unable to find any valuable Window provider. 
[CRITICAL] [App         ] Unable to get a Window, abort.

After changing line 2 to os.environ['KIVY_WINDOW'] = 'x11', got the following results:

[DEBUG  ] [Window      ] Provider <sdl2> ignored by config
[DEBUG  ] [Window      ] Ignored <x11> (import error)
[CRITICAL] [Window      ] Unable to find any valuable Window provider. 
x11 - ModuleNotFoundError: No module named 'kivy.core.window.window_x11'
  File "/usr/local/lib/python3.7/dist-packages/kivy/core/__init__.py", line 63, in core_select_lib
    fromlist=[modulename], level=0)
[CRITICAL] [App         ] Unable to get a Window, abort.

[Lauszus]

Here are the instructions on how to install and run a Kivy app at boot on Buster lite:

First install xserver-org, as we need it to show the actual window:

sudo apt-get -y install xserver-xorg

Next I install nodm from source, so it includes the following fix: https://github.com/spanezz/nodm/pull/10:

sudo apt-get -y install libpam0g-dev help2man libx11-dev debhelper
git clone https://github.com/slashblog/nodm.git
pushd nodm
    git checkout d48a8f6266d3f464138e0e95b65896917c35c89f
    source /etc/os-release  # Will set the 'VERSION' variable
    if [ "$(echo $VERSION | sed -En 's/[0-9]+ \(([a-z]+)\)/\1/p')" == "buster" ]; then
        wget http://deb.debian.org/debian/pool/main/n/nodm/nodm_0.13-5.debian.tar.xz
    else
        wget http://deb.debian.org/debian/pool/main/n/nodm/nodm_0.13-1.3.debian.tar.xz
    fi
    tar xf nodm_0.13-*.debian.tar.xz
    sudo dpkg-buildpackage -us -uc -b
popd
sudo dpkg -i nodm_0.13-*_armhf.deb
sudo rm -rf nodm*

Now enable graphical login:

sudo systemctl set-default graphical.target

Configure nodm and start our app at boot:

# Has the same effect as calling 'sudo dpkg-reconfigure nodm'
sudo sh -c 'echo "NODM_ENABLED=true" > /etc/default/nodm'
sudo sh -c 'echo "NODM_USER=$SUDO_USER" >> /etc/default/nodm' # Note that the variable SUDO_USER is used
sudo sh -c 'echo "NODM_FIRST_VT='\''7'\''" >> /etc/default/nodm'
sudo sh -c 'echo "NODM_XSESSION=/etc/X11/Xsession" >> /etc/default/nodm'
sudo sh -c 'echo "NODM_X_OPTIONS='\''-nolisten tcp'\''" >> /etc/default/nodm'
sudo sh -c 'echo "NODM_MIN_SESSION_TIME=60" >> /etc/default/nodm'
sudo sh -c 'echo "NODM_X_TIMEOUT=300" >> /etc/default/nodm'

# Start the app using nodm
echo '#!/bin/bash' > ~/.xsession
echo 'export DISPLAY=:0.0' >> ~/.xsession
echo "~/venv-kivy/bin/python3 ~/app.py" >> ~/.xsession

Setup a virtual enveriment:

sudo apt-get -y install python3-pip python3-venv
sudo pip3 install -U pip
python3 -m venv venv-kivy
source ~/venv-kivy/bin/activate

Install Kivy dependencies:

sudo apt-get -y install python3-dev libmtdev1 libsdl2-dev libsdl2-image-dev libsdl2-mixer-dev libsdl2-ttf-dev
sudo apt-get -y install pkg-config libgl1-mesa-dev libgles2-mesa-dev libgstreamer1.0-dev gstreamer1.0-plugins-{bad,base,good,ugly} gstreamer1.0-{omx,alsa} libmtdev-dev
pip3 install -U pygments docutils Cython==0.29.10 wheel

Now it’s time for compiling and installing Kivy. Note that I use my fork with a patch, so it does not use the proprietary Broadcom drivers that are not available on the Raspberry Pi 4 (https://github.com/Lauszus/kivy/commit/9cdcada34a6149b7fd6bd4c57285afc828d69948):

export VIDEOCOREMESA=1; pip3 install git+https://github.com/Lauszus/kivy.git@rpi4_auto#egg=kivy

Finally create a small test app:

cat <<EOF > ~/app.py
from kivy.app import App
from kivy.uix.button import Button


class TestApp(App):

    def build(self):
        return Button(text='hello world')


if __name__ == '__main__':
    TestApp().run()
EOF

Now reboot and enjoy 😃

[matham]

I encountered failed to add service - already in use? on buster full, when trying to use the egl_rpi backend. Fixing it by commenting out dtoverlay=vc4-kms-v3d in /boot/config.txt made the error go away, but then kivy didn’t show anything at all.

I wonder if it’s the same on buster lite?