Exception ignored in: 'kivy.graphics.instructions.RenderContext.set_texture'

[GardaNegara]

Versions

• Python: 3.6.7
• OS: Debian Testing
• Kivy: 1.10.1
• Kivy installation method: pip in a virtualenv per the official installation instructions. I've made sure I have the correct version of Cython (0.25.2).

Description

I've successfully run the Pong tutorial without hiccups. However, the following Hello World code taken from the book Kivy: Interactive Applications in Python - Second Edition generates an exception and the buttons appear garbled/corrupted.

Code and Logs

## widgets.py
from kivy.app import App
from kivy.uix.widget import Widget

class MyWidget(Widget):
        pass

class WidgetsApp(App):
        def build(self):
                return MyWidget()

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

## widgets.kv
<MyWidget>:
        Button:
                text: 'Hello'
                font_size: 32
                color: .8, .9, 1
                pos: 0, 100
                size: 100, 50
        Button:
                text: 'World!'
                font_size: 32
                color: .8, .9, 1
                pos: 100, 0
                size: 100, 50

Here is the log:

[INFO   ] Logger: Record log in /home/garda/.kivy/logs/kivy_18-11-08_5.txt
[INFO   ] Kivy: v1.10.1
[INFO   ] Python: v3.6.7 (default, Oct 21 2018, 08:08:16) 
[GCC 8.2.0]
[INFO   ] Factory: 194 symbols loaded
[INFO   ] Image: Providers: img_tex, img_dds, img_sdl2, img_gif (img_pil, img_ffpyplayer ignored)
[INFO   ] Window: Provider: sdl2(['window_egl_rpi'] ignored)
[INFO   ] GL: Using the "OpenGL" graphics system
[INFO   ] GL: Backend used <gl>
[INFO   ] GL: OpenGL version <b'2.1 Mesa 18.1.9'>
[INFO   ] GL: OpenGL vendor <b'Intel Open Source Technology Center'>
[INFO   ] GL: OpenGL renderer <b'Mesa DRI Intel(R) 965GM '>
[INFO   ] GL: OpenGL parsed version: 2, 1
[INFO   ] GL: Shading version <b'1.20'>
[INFO   ] GL: Texture max size <8192>
[INFO   ] GL: Texture max units <16>
[INFO   ] Window: auto add sdl2 input provider
[INFO   ] Window: virtual keyboard not allowed, single mode, not docked
[INFO   ] Text: Provider: sdl2
[INFO   ] Base: Start application main loop
[INFO   ] GL: NPOT texture support is available
[WARNING] stderr: Exception ignored in: 'kivy.graphics.instructions.RenderContext.set_texture'
[WARNING] stderr: Traceback (most recent call last):
[WARNING] stderr:   File "kivy/graphics/texture.pyx", line 789, in kivy.graphics.texture.Texture.bind (/tmp/pip-install-8jmcdld_/kivy/kivy/graphics/texture.c:11612)
[WARNING] stderr:   File "/media/Plain/Codes/kivy/lib/python3.6/site-packages/kivy/core/text/__init__.py", line 662, in _texture_fill
[WARNING] stderr:     self.render(real=True)
[WARNING] stderr:   File "/media/Plain/Codes/kivy/lib/python3.6/site-packages/kivy/core/text/__init__.py", line 603, in render
[WARNING] stderr:     return self._render_real()
[WARNING] stderr:   File "/media/Plain/Codes/kivy/lib/python3.6/site-packages/kivy/core/text/__init__.py", line 586, in _render_real
[WARNING] stderr:     self.render_lines(lines, options, self._render_text, y, size)
[WARNING] stderr:   File "/media/Plain/Codes/kivy/lib/python3.6/site-packages/kivy/core/text/__init__.py", line 564, in render_lines
[WARNING] stderr:     render_text(line, x, y)
[WARNING] stderr:   File "/media/Plain/Codes/kivy/lib/python3.6/site-packages/kivy/core/text/text_sdl2.py", line 48, in _render_text
[WARNING] stderr:     self._surface.render(self, text, x, y)
[WARNING] stderr:   File "kivy/core/text/_text_sdl2.pyx", line 127, in kivy.core.text._text_sdl2._SurfaceContainer.render (/tmp/pip-install-8jmcdld_/kivy/kivy/core/text/_text_sdl2.c:2535)
[WARNING] stderr: IndexError: list index out of range
[WARNING] stderr: Exception ignored in: 'kivy.graphics.instructions.RenderContext.set_texture'
[WARNING] stderr: Traceback (most recent call last):
[WARNING] stderr:   File "kivy/graphics/texture.pyx", line 789, in kivy.graphics.texture.Texture.bind (/tmp/pip-install-8jmcdld_/kivy/kivy/graphics/texture.c:11612)
[WARNING] stderr:   File "/media/Plain/Codes/kivy/lib/python3.6/site-packages/kivy/core/text/__init__.py", line 662, in _texture_fill
[WARNING] stderr:     self.render(real=True)
[WARNING] stderr:   File "/media/Plain/Codes/kivy/lib/python3.6/site-packages/kivy/core/text/__init__.py", line 603, in render
[WARNING] stderr:     return self._render_real()
[WARNING] stderr:   File "/media/Plain/Codes/kivy/lib/python3.6/site-packages/kivy/core/text/__init__.py", line 586, in _render_real
[WARNING] stderr:     self.render_lines(lines, options, self._render_text, y, size)
[WARNING] stderr:   File "/media/Plain/Codes/kivy/lib/python3.6/site-packages/kivy/core/text/__init__.py", line 564, in render_lines
[WARNING] stderr:     render_text(line, x, y)
[WARNING] stderr:   File "/media/Plain/Codes/kivy/lib/python3.6/site-packages/kivy/core/text/text_sdl2.py", line 48, in _render_text
[WARNING] stderr:     self._surface.render(self, text, x, y)
[WARNING] stderr:   File "kivy/core/text/_text_sdl2.pyx", line 127, in kivy.core.text._text_sdl2._SurfaceContainer.render (/tmp/pip-install-8jmcdld_/kivy/kivy/core/text/_text_sdl2.c:2535)
[WARNING] stderr: IndexError: list index out of range
[INFO   ] Base: Leaving application in progress...

[Fak3]

Same error here, python 3.7.2

[Fak3]

Error disappears if color: is changed to have alpha value, like this: color: .8, .9, 1, 1

[Israelmath]

I had the same error and, after search a lot and almost punched my pc, I change the color and now it works well...

[pythonic64]

Button class inherits from Label which has color property in rgba format, so you have to set color in that format to change the color of displayed text. See https://kivy.org/doc/stable/api-kivy.uix.label.html#kivy.uix.label.Label.color .
Maybe a good solution would be to replace ListProperty with ColorProperty for all color-like properties in Kivy widgets.

[pythonic64]

Pull request #6918 replaces ListProperty with ColorProperty, so setting color in rgb format will use 1.0 as alpha value and not raise an error. Also a string in format #rrggbb or #rrggbbaa can be used to set the value for color.

[pythonic64]

Fixed in #6918.