egui_glow: `NoAvailablePixelFormat`

[rnd-ash]

Describe the bug This occurs when running an egui application on a system without a openGL 3.1 capable GPU. However according to glow, it should be possible to stop this from happening by disabling MSAA, but I cannot find any way to do so.

I've tried this with both backends available for EGUI and both end up with the same error.

Interestingly, when setting LLVMpipe (Mesa-dist-win) in windows to get OpenGL software rendering even OpenGL 4 applications can open and run fine, but EGUI apps still crash!

here is an OpenGL 4.5 app running on my VM using LLVMPipe rendering:

To Reproduce Steps to reproduce the behavior:

1. Optional - Install mesa-dist-win for software OpenGL rendering
2. Launch any egui app in a headless system or virtual machine (Virtualbox or Qemu)
3. Experience the crash

Desktop (please complete the following information):

• OS: Windows 11 (Virtualized with Qemu + QXL Display)

Backtrace

Reason: panicked at 'called `Result::unwrap()` on an `Err` value: NoAvailablePixelFormat', \.cargo\registry\src\github.com-1ecc6299db9ec823\egui_glow-0.15.0\src\epi_backend.rs:48:14
Backtrace:
  0: <unknown>
  1: <unknown>
  2: <unknown>
  3: <unknown>
  4: <unknown>
  5: <unknown>
  6: <unknown>
  7: <unknown>
  8: <unknown>
  9: <unknown>
 10: <unknown>
 11: <unknown>
 12: <unknown>
 13: <unknown>
 14: BaseThreadInitThunk
 15: RtlGetFullPathName_UEx
 16: RtlGetFullPathName_UEx

[parasyte]

The error is from glutin. This is what they have to say about it: https://github.com/rust-windowing/glutin/blob/master/ISSUES.md

I don't know how useful this information is. Many of the glutin issues referencing the error come to the conclusion that the vendor/driver does not support the requested features. The panic is here at the unwrap: https://github.com/emilk/egui/blob/08cc07bb2d12f06d086b2baf3f1db424a933401f/egui_glow/src/epi_backend.rs#L42-L48

[bhutch29]

I am getting the same issue. My egui application runs fine on Linux and on a Windows machine, but when running it on a Windows VM guest (Linux host) with either glium or glow backends it crashes. Here is the backtrace using the glow backend:

thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: NoAvailablePixelFormat', /cargo/registry/src/github.com-1ecc6299db9ec823/egui_glow-0.15.0/src/epi_backend.rs:48:14
stack backtrace:
   0: rust_begin_unwind
             at /rustc/f1edd0429582dd29cccacaf50fd134b05593bd9c\/library\std\src/panicking.rs:517:5
   1: core::panicking::panic_fmt
             at /rustc/f1edd0429582dd29cccacaf50fd134b05593bd9c\/library\core\src/panicking.rs:100:14
   2: core::result::unwrap_failed
             at /rustc/f1edd0429582dd29cccacaf50fd134b05593bd9c\/library\core\src/result.rs:1616:5
   3: core::result::Result<T,E>::unwrap
             at /rustc/f1edd0429582dd29cccacaf50fd134b05593bd9c\library\core\src\result.rs:1298:23
   4: egui_glow::epi_backend::create_display
             at /cargo/registry/src/github.com-1ecc6299db9ec823/egui_glow-0.15.0/src/epi_backend.rs:42:9
   5: egui_glow::epi_backend::run
             at /cargo/registry/src/github.com-1ecc6299db9ec823/egui_glow-0.15.0/src/epi_backend.rs:89:27
   6: eframe::run_native
             at /cargo/registry/src/github.com-1ecc6299db9ec823/eframe-0.15.0/src/lib.rs:156:5
   7: siggen_toolkit::gui::run
             at /project/src/gui.rs:729:5
   8: siggen_toolkit::main
             at /project/src/main.rs:17:9
   9: core::ops::function::FnOnce::call_once
             at /rustc/f1edd0429582dd29cccacaf50fd134b05593bd9c\library\core\src\ops\function.rs:227:5

[not-matthias]

Is there any workaround to this? Can't really figure out why it's not working inside my KVM.

[kurbatxx]

Run app on llvmpipe. Сhange to .with_srgb(false) https://github.com/emilk/egui/blob/898f4804b7b998ffeb1ff9f457b935e1364d6827/eframe/src/native/run.rs#L27-L38

Screenshot

[vaniusrb]

Thank you @kurbatxx! It worked very well for me. Hope the egui can have this configuration soon.

[20iahazban]

hello guys,

i have a weird error when my egui application name is "Me": thread 'main' panicked at 'called Result::unwrap() on an Err value: NoAvailablePixelFormat' I have the same error if i just rename one of my egui application to "me.exe" Im working on windows. Do you have any suggestion? How the executable name can influence the runtime?

[emilk]

@20iahazban probably due to saved state: https://docs.rs/eframe/latest/eframe/trait.App.html#method.save

Please check that the bad value is in the stored state (maybe a negative inner_size_points or position?), then maybe we can fix it!

[20iahazban]

Hello @emilk,

thanks for the answer. (I love using egui by the way) Im not using this method at all. "Persistence" feature is not enabled.