wgpu-hal ran into a preventable internal error: {txt}

Error message

wgpu-hal ran into a preventable internal error: {txt}

What it means

This panic is wgpu-hal's generic internal error hook for failures that are not invariant violations (usage errors) but still indicate a preventable problem inside a HAL backend implementation. It is raised via `hal_internal_error`, a cold `panic!` helper in wgpu-hal/src/lib.rs, meaning a backend hit an unexpected condition that upstream validation should normally have prevented. Because it is a panic (not a Result), it aborts the calling thread and indicates a wgpu bug or mis-wired backend rather than ordinary user error.

Source

Thrown at wgpu-hal/src/lib.rs:517

        gpu_allocator::AllocationSizes::new(
            value.min_device_memblock_size,
            value.min_host_memblock_size,
        )
        .with_max_device_memblock_size(value.max_device_memblock_size)
        .with_max_host_memblock_size(value.max_host_memblock_size)
    }
}

#[allow(dead_code, reason = "may be unused on some platforms")]
#[cold]
fn hal_usage_error<T: fmt::Display>(txt: T) -> ! {
    panic!("wgpu-hal invariant was violated (usage error): {txt}")
}

#[allow(dead_code, reason = "may be unused on some platforms")]
#[cold]
fn hal_internal_error<T: fmt::Display>(txt: T) -> ! {
    panic!("wgpu-hal ran into a preventable internal error: {txt}")
}

#[derive(Clone, Debug, Eq, PartialEq, Error)]
pub enum ShaderError {
    #[error("Compilation failed: {0:?}")]
    Compilation(String),
    #[error(transparent)]
    Device(#[from] DeviceError),
}

#[derive(Clone, Debug, Eq, PartialEq, Error)]
pub enum PipelineError {
    #[error("Linkage failed for stage {0:?}: {1}")]
    Linkage(wgt::ShaderStages, String),
    #[error("Entry point for stage {0:?} is invalid")]
    EntryPoint(naga::ShaderStage),
    #[error(transparent)]
    Device(#[from] DeviceError),

View on GitHub (pinned to 3e11ff59bf)

Solutions

Reproduce with WGPU_BACKTRACE=1 to get a stack trace and file a wgpu issue with the message and backend/driver info
Check that required wgpu::Features are requested on the device before using the feature that panicked
Update wgpu to the latest version in case the backend bug is already fixed
If using wgpu-hal directly, add the missing validation/check that the invariant expects

Example fix

// before
let device = adapter.request_device(&desc, None)?; // desc.features = Features::empty()
shader uses feature X -> hal_internal_error
// after
let mut features = wgt::Features::empty();
features.insert(wgt::Features::EXPERIMENTAL_X);
let device = adapter.request_device(&DeviceDescriptor { features, ..Default::default() }, None)?;

Defensive patterns

Strategy: validation

Validate before calling

if !device.features().contains(required_feature) {
    panic/return Err("feature X not enabled for this device");
}

Try / catch

std::panic::catch_unwind(|| device.create_render_pipeline(&desc))

Prevention

Request all required wgpu::Features on device creation
Keep wgpu updated to pick up backend fixes
Report panics with WGPU_BACKTRACE=1 output to the wgpu issue tracker

When it happens

Trigger: Any wgpu-hal backend code path that calls `hal_internal_error(...)` when a backend-specific condition cannot be fulfilled at runtime (e.g. a device/adapter capability or surface configuration that the backend assumed valid but turns out not to be). It is the companion of `hal_usage_error` (invariant violations) and is never intentionally triggered by user API calls.

Common situations: Hitting a backend bug while using bleeding-edge or experimental features (ray tracing, etc.), running on a driver with unusual behavior, or using wgpu internals directly (e.g. writing a custom backend or bypassing wgpu-core validation). Also seen when a feature gate is missing so a capability check fails deep in the HAL.

Related errors

AI-assisted analysis of gfx-rs/wgpu@3e11ff59bf (2026-09-03). Data as JSON: /api/errors/e8be110ae705b51e. Report an issue: GitHub.