linux + vulkan crashes on old gpus `Shader requires capability Capabilities(SHADER_FLOAT16_IN_FLOAT32)`

[mq1]

Is your issue REALLY a bug?

• My issue is indeed a bug!
• I am not crazy! I will not fill out this form just to ask a question or request a feature. Pinky promise.

Is there an existing issue for this?

• I have searched the existing issues.

Is this issue related to iced?

• My hardware is compatible and my graphics drivers are up-to-date.

What happened?

Iced straight up crashes when a vulkan adapter is found (so the fallback is not triggered), but it's incompatible (doesn't support some features).

related issues:

• [Bug] wgpu error: Validation Error after update to 5.1.8 mq1/TinyWiiBackupManager#546
• [Help] Impactor (v. 2.0.0 and up) refuses to open on Linux (mint 22.3) claration/Impactor#103

we were able to find a workaround for this issue:

• claration/Impactor@657f827
• mq1/TinyWiiBackupManager@287c287

What is the expected behavior?

The program should switch to the fallback renderer when wgpu crashes

Version

crates.io release

Operating System

Linux

Do you have any log output?

[edwloef]

Does this still occur on the master branch?

Context:

• wgpu: request devices with SHADER_F16 feature #3164
• Enable SHADER_F16 feature only when available #3183

[mq1]

Does this still occur on the master branch?

Context:

• wgpu: request devices with SHADER_F16 feature #3164
• Enable SHADER_F16 feature only when available #3183

unfortunately i can't test this as the issue was on a user's pc, but it seems to be the exact thing i reported.

should we keep this issue open until iced 0.15 is out as my report includes a workaround?

[andvary]

In my case the issue persists on the master branch (6d5eb86):

wgpu error: Validation Error

Caused by:
  In Device::create_shader_module, label = 'iced_wgpu.quad.solid.shader'
    
Shader validation error: Function [1] 'unpack_u32' is invalid
   ┌─ iced_wgpu.quad.solid.shader:9:1
   │  
 9 │ ╭ fn unpack_u32(data: vec2<u32>) -> vec4<f32> {
10 │ │     let rg: vec2<f32> = unpack2x16float(data.x);
   │ │                         ^^^^^^^^^^^^^^^ naga::ir::Expression [2]
11 │ │     let ba: vec2<f32> = unpack2x16float(data.y);
12 │ │ 
13 │ │     return vec4<f32>(rg.y, rg.x, ba.y, ba.x);
   │ ╰─────────────────────────────────────────────^ naga::ir::Function [1]
   │  
   = Expression [2] is invalid
   = Shader requires capability Capabilities(SHADER_FLOAT16_IN_FLOAT32)

[edwloef]

Looking back, I suspect #3183 actually re-broke this. Only asking for the capability if the device already has that capability seems like a no-op, and doesn't help if a shader needs the device to support that capability.

[andvary]

Looking back, I suspect #3183 actually re-broke this. Only asking for the capability if the device already has that capability seems like a no-op, and doesn't help if a shader needs the device to support that capability.

I tried building my app with Iced on commit that precedes the one you mentioned (15c0e39) and it runs fine, so guess you are right.