tracking: Black screen on Nvidia Linux due to WGPU GPU selection

[saghen]

For some reason, wgpu seems to think I have an IGPU (on a 9950x3d) and attempts to render with it, leading to a black screen. I was able to override the GPU selection with WGPU_POWER_PREF='high', forcing it to prefer my discrete GPU (related issue). Would it make sense to make this a default in the nixos module?

Logs

thread '' panicked at /nix/store/eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee-vendor-cargo-deps/c19b7c6f923b580ac259164a89f2577984ad5ab09ee9d583b888f934adbbe8d0/sqlite-0.36.1/src/cursor.rs:159:31:
called `Result::unwrap()` on an `Err` value: Error { code: None, message: Some("failed to convert") }
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
2025-04-25T20:37:12.721Z INFO  [wgpu_hal::vulkan::instance] Debug utils not enabled: debug_utils_user_data not passed to Instance::from_raw
2025-04-25T20:37:12.729Z INFO  [wgpu_hal::gles::egl] Using Wayland platform
2025-04-25T20:37:12.730Z WARN  [wgpu_hal::gles::egl] No config found!
2025-04-25T20:37:12.730Z WARN  [wgpu_hal::gles::egl] EGL says it can present to the window but not natively
2025-04-25T20:37:12.737Z INFO  [iced_wgpu::window::compositor] Settings {
    present_mode: AutoVsync,
    backends: Backends(
        VULKAN | GL | METAL | DX12 | BROWSER_WEBGPU,
    ),
    default_font: Font {
        family: Name(
            "FiraCode Nerd Font",
        ),
        weight: Normal,
        stretch: Normal,
        style: Normal,
    },
    default_text_size: Pixels(
        14.0,
    ),
    antialiasing: None,
}
2025-04-25T20:37:12.742Z INFO  [wgpu_core::instance] Adapter Vulkan AdapterInfo { name: "NVIDIA GeForce RTX 3090", vendor: 4318, device: 8708, device_type: DiscreteGpu, driver: "NVIDIA", driver_info: "570.133.07", backend: Vulkan }
2025-04-25T20:37:12.742Z INFO  [wgpu_core::instance] Adapter Vulkan AdapterInfo { name: "AMD Radeon Graphics (RADV RAPHAEL_MENDOCINO)", vendor: 4098, device: 5056, device_type: IntegratedGpu, driver: "radv", driver_info: "Mesa 25.0.3", backend: Vulkan }
2025-04-25T20:37:12.742Z INFO  [wgpu_core::instance] Adapter Vulkan AdapterInfo { name: "llvmpipe (LLVM 19.1.7, 256 bits)", vendor: 65541, device: 0, device_type: Cpu, driver: "llvmpipe", driver_info: "Mesa 25.0.3 (LLVM 19.1.7)", backend: Vulkan }
2025-04-25T20:37:12.779Z INFO  [wgpu_core::instance] Adapter Gl AdapterInfo { name: "NVIDIA GeForce RTX 3090/PCIe/SSE2", vendor: 4318, device: 0, device_type: Other, driver: "", driver_info: "", backend: Gl }
2025-04-25T20:37:12.779Z INFO  [iced_wgpu::window::compositor] Available adapters: [
    AdapterInfo {
        name: "NVIDIA GeForce RTX 3090",
        vendor: 4318,
        device: 8708,
        device_type: DiscreteGpu,
        driver: "NVIDIA",
        driver_info: "570.133.07",
        backend: Vulkan,
    },
    AdapterInfo {
        name: "AMD Radeon Graphics (RADV RAPHAEL_MENDOCINO)",
        vendor: 4098,
        device: 5056,
        device_type: IntegratedGpu,
        driver: "radv",
        driver_info: "Mesa 25.0.3",
        backend: Vulkan,
    },
    AdapterInfo {
        name: "llvmpipe (LLVM 19.1.7, 256 bits)",
        vendor: 65541,
        device: 0,
        device_type: Cpu,
        driver: "llvmpipe",
        driver_info: "Mesa 25.0.3 (LLVM 19.1.7)",
        backend: Vulkan,
    },
    AdapterInfo {
        name: "NVIDIA GeForce RTX 3090/PCIe/SSE2",
        vendor: 4318,
        device: 0,
        device_type: Other,
        driver: "",
        driver_info: "",
        backend: Gl,
    },
]
2025-04-25T20:37:12.782Z INFO  [wgpu_core::instance] Adapter Vulkan AdapterInfo { name: "AMD Radeon Graphics (RADV RAPHAEL_MENDOCINO)", vendor: 4098, device: 5056, device_type: IntegratedGpu, driver: "radv", driver_info: "Mesa 25.0.3", backend: Vulkan }
2025-04-25T20:37:12.782Z INFO  [iced_wgpu::window::compositor] Selected: AdapterInfo {
    name: "AMD Radeon Graphics (RADV RAPHAEL_MENDOCINO)",
    vendor: 4098,
    device: 5056,
    device_type: IntegratedGpu,
    driver: "radv",
    driver_info: "Mesa 25.0.3",
    backend: Vulkan,
}
2025-04-25T20:37:12.782Z INFO  [iced_wgpu::window::compositor] Available formats: Copied {
    it: Iter(
        [
            Rgba8UnormSrgb,
            Bgra8UnormSrgb,
            Rgba8Unorm,
            Bgra8Unorm,
        ],
    ),
}
2025-04-25T20:37:12.782Z INFO  [iced_wgpu::window::compositor] Available alpha modes: [
    Opaque,
    PreMultiplied,
]
2025-04-25T20:37:12.782Z INFO  [iced_wgpu::window::compositor] Selected format: Rgba8UnormSrgb with alpha mode: PreMultiplied

[friedow]

Yes, I think making WGPU_POWER_PREF='high' a default in the nixos module is a good idea until iced-rs/iced#2810 is resolved properly. Feel free to send a PR for that.

I'll keep this issue open to track iced-rs/iced#2810 and revert the environment variable, once this gets fixed upstream.