gfx-rs/wgpu · error

TIMESTAMP_QUERY_INSIDE_ENCODERS feature must be enabled to c

Error message

TIMESTAMP_QUERY_INSIDE_ENCODERS feature must be enabled to call write_timestamp on a command encoder.

What it means

On the WebGPU backend, CommandEncoder::write_timestamp is unconditionally unsupported: the write-timestamp-on-encoder capability was removed from the WebGPU spec (gpuweb PR #4370). wgpu panics to signal that this backend can never service the call.

Source

Thrown at wgpu/src/backend/webgpu.rs:3552

        }
    }

    fn insert_debug_marker(&self, label: &str) {
        self.inner.insert_debug_marker(label)
    }

    fn push_debug_group(&self, group_label: &str) {
        self.inner.push_debug_group(group_label)
    }

    fn pop_debug_group(&self) {
        self.inner.pop_debug_group()
    }

    fn write_timestamp(&self, _query_set: &dispatch::DispatchQuerySet, _query_index: u32) {
        // Not available on WebGPU.
        // This was part of the spec originally but got removed, see https://github.com/gpuweb/gpuweb/pull/4370
        panic!("TIMESTAMP_QUERY_INSIDE_ENCODERS feature must be enabled to call write_timestamp on a command encoder.")
    }

    fn resolve_query_set(
        &self,
        query_set: &dispatch::DispatchQuerySet,
        first_query: u32,
        query_count: u32,
        destination: &dispatch::DispatchBuffer,
        destination_offset: crate::BufferAddress,
    ) {
        let query_set = &query_set.as_webgpu().inner;
        let destination = &destination.as_webgpu().inner;

        self.inner.resolve_query_set_with_u32(
            query_set,
            first_query,
            query_count,
            destination,

View on GitHub (pinned to 3e11ff59bf)

Solutions

1. Guard encoder-level write_timestamp calls behind a runtime backend check and skip them on WebGPU.
2. Move timestamp writes into render/compute passes via pass-level write_timestamp where TIMESTAMP_QUERY_INSIDE_PASSES is supported.
3. Fall back to CPU-side timing on web.
4. Gate the profiling feature on adapter.features() at startup.

Example fix

// before
encoder.write_timestamp(&query_set, 0);
// after
if features.contains(Features::TIMESTAMP_QUERY_INSIDE_ENCODERS) && !is_webgpu {
    encoder.write_timestamp(&query_set, 0);
}

let ok = device.features().contains(Features::TIMESTAMP_QUERY_INSIDE_ENCODERS)
    && adapter.get_info().backend != wgpu::Backend::Browser;
if ok { encoder.write_timestamp(&qs, 0); }

fn supports_encoder_timestamps(f: Features, b: Backend) -> bool {
    f.contains(Features::TIMESTAMP_QUERY_INSIDE_ENCODERS) && b != Backend::Browser
}

When it happens

Trigger: Calling command_encoder.write_timestamp(query_set, query_index) when running on the WebGPU (browser/wasm) backend, regardless of feature flags.

Common situations: wasm builds of an app using GPU timestamp profiling on native; shared profiling code paths that call write_timestamp on encoders without checking the backend; assuming TIMESTAMP_QUERY_INSIDE_ENCODERS makes the call valid on web.

Related errors

• TIMESTAMP_QUERY_INSIDE_PASSES feature must be enabled to cal
• {:?} is not enabled for this backend
• VERTEX_ATTRIBUTE_64BIT feature must be enabled to use Double
• IMMEDIATES feature must be enabled to call set_immediates
• MESH_SHADER feature must be enabled to call draw_mesh_tasks

AI-assisted analysis of gfx-rs/wgpu@3e11ff59bf (2026-09-03). Data as JSON: /api/errors/b3614777e708cdf0. Report an issue: GitHub.