Crash with SDL2's Metal renderer.
tiessa opened this issue · 9 comments
Sometimes I receive the error:
-[MTLRenderPipelineDescriptorInternal validateWithDevice:]:2400: failed assertion `No valid pixelFormats set.'
And python crashes completely. How would you advise me helping to isolate the error?
What is your OS? I assume it's some version of MacOS based on the error.
You can use python -m trace --trace my_script.py to get the last Python line before the crash.
Try setting the environment variable SDL_RENDER_DRIVER=software before starting the script. This will avoid using Metal for graphics rendering and should at least give you a different error.
Mac OS 10.13.4
I'll add those when I run my program and when it dies again (if it does), I'll update this thread.
SDL_RENDER_DRIVER=software
Seems to have solved it - instead of crashing every 5 times I ran it, it hasn't crashed in days.
Thank you!
I don't think I'll be able to reproduce this since it might only be a problem with SDL2 and Metal. This could be from SDL2's Metal support being fairly new, but I don't know much about it.
I'd be nice if you checked other SDL2 programs to see if the same issue happens. Python-tcod is currently on SDL2.0.10. Metal support was added in SDL2.0.8.
I don't think you will able to reproduce it either. I tried any number of things to narrow it down, but couldn't figure out the trigger. I wish I could have and made your life easier.
I'm mainly thinking it might be something to put in the docs as a faq, "if you're having crashing problems on the mac, try..."
I don't know of any other SDL programs that I use, I'm sorry otherwise I would.
One way or the other, thank you for picking up the support for tcod and improving it! Your work is appreciated.
One more thing, before using the SDL software renderer, it would take a second sometimes to update a screen of about 80x40 characters and otherwise run at about 17 ms for an update of a smaller part of it. Now, it doesn't have the big pause and consistently hits <4 ms for an update.
I think SDL support for metal has a long way to go before its a useable alternative.
Don't worry about it if you can't pinpoint what the cause is.
I think MacOS still supports OpenGL, so SDL_RENDER_DRIVER=opengl should give better performance (assuming tcod's renderer is set to tcod.RENDERER_SDL2.) There's also tcod.RENDERER_OPENGL2, but that's slightly less cross-platform.
I played with the various renderers with the sample program - one of the OpenGL ones just outright crashed every time. I think it was OpenGL2 even, which seemed strange to me, going with the theory that everything new is better :D
I didn't realize I could specify the SDL renderer separate from the tcod one. I went and set SDL_RENDER_DRIVER=opengl right now and it went back to the 17ms and crashed.
Closing this as the issues are more with SDL and MacOS hardware than with Python-tcod, and the workarounds are known.
Python-tcod keeps up with the latest version of SDL, so it's possible this was fixed by one of the newer versions.
Anyone still having this issue can try the SDL_RENDER_DRIVER=software hint as a last resort workaround. This hint can be set from Python with os.environ["SDL_RENDER_DRIVER"] = "software" before initializing the libtcod context or touching SDL initialization.
Other options for SDL_RENDER_DRIVER are documented here.