[ExecuTorch][WebGPU] Select emdawnwebgpu for Emscripten builds

[JCNTH]

Stack from ghstack (oldest at bottom):

• [ExecuTorch][WebGPU] Lift FastVLM dispatch limits and harden graph construction #21602
• [ExecuTorch][WebGPU] Cover Conv1d routes and dynamic manifests #21601
• [ExecuTorch][WebGPU] Support general groups=1 Conv1d #21600
• [ExecuTorch][WebGPU] Test byte-packed BOOL tails #21599
• [ExecuTorch][WebGPU] Support byte-packed BOOL storage #21598
• [ExecuTorch][Vulkan] Preserve persistent buffer mutations #21597
• [ExecuTorch][WebGPU] Preserve Linear and Q4 embedding params across dynamic resize #21483
• [ExecuTorch][WebGPU] Generate logical and arithmetic binary shader variants #21451
• [ExecuTorch][WebGPU] Generate extrema and unary shader variants #21450
• [ExecuTorch][WebGPU] Generate typed to_copy shader variants #21449
• [ExecuTorch][WebGPU] Make WGSL generation rollback-safe #21448
• [ExecuTorch][WebGPU] Add Qwen3 K16 attention and fp16 KV cache #21136
• [ExecuTorch][WebGPU] Add HuggingFace rotate-half RoPE #21135
• [ExecuTorch][WebGPU] Repair dynamic SDPA routing, add attestation #21134
• -> [ExecuTorch][WebGPU] Select emdawnwebgpu for Emscripten builds #21133
• [ExecuTorch][WebGPU] Add Llama K16 online causal attention #21132
• [ExecuTorch][WebGPU] Replace broad QKV fusion with BK64 kernel #21131
• [ExecuTorch][WebGPU] Route exact prefill shapes to the BK64 GEMM #21130
• [ExecuTorch][WebGPU] Fuse the SwiGLU elementwise chain #21129
• [ExecuTorch][WebGPU] Coordinate dynamic dispatch routes #21128
• [ExecuTorch][WebGPU] Add certified scoped output suppression #21127

Building the WebGPU backend for the browser previously required a manual
source-tree patch to pick the right WebGPU implementation. This makes the CMake
configuration select the emdawnwebgpu port for Emscripten builds while native
builds keep Dawn and their platform libraries, so the production kernel stack
builds for the browser unpatched. Build-system integration only; no model or
kernel behavior changes.

Key changes:

• CMakeLists.txt: choose emdawnwebgpu under Emscripten, Dawn otherwise.
• test/test_cmake_configuration.py: contract test asserting the selection.
  @exported-using-ghexport

Differential Revision: D113171750

Differential Revision: D113171750

[pytorch-bot]

🔗 Helpful Links

🧪 See artifacts and rendered test results at hud.pytorch.org/pr/pytorch/executorch/21133

• 📄 Preview Python docs built from this PR

Note: Links to docs will display an error until the docs builds have been completed.

❌ 40 New Failures, 28 Pending

As of commit 8585c43 with merge base 28a7fac ():

NEW FAILURES - The following jobs have failed:

• Cadence Build & Test / cpu-test / test-aot / test-aot (gh)
  ##[error]API rate limit exceeded for installation. If you reach out to GitHub Support for help, please include the request ID D6E4:157945:882F541:1C975407:6A760B59 and timestamp 2026-08-07 16:44:09 UTC. For more on scraping GitHub and how it may affect your rights, please review our Terms of Service (https://docs.github.com/en/site-policy/github-terms/github-terms-of-service) - https://docs.github.com/en/rest/using-the-rest-api/getting-started-with-the-rest-api#rate-limiting
• Cadence Build & Test / cpu-test / test-ops / test-ops (gh)
  ##[error]API rate limit exceeded for installation. If you reach out to GitHub Support for help, please include the request ID ECDE:2C3D6C:4C4A414:1024EBC6:6A760B58 and timestamp 2026-08-07 16:44:08 UTC. For more on scraping GitHub and how it may affect your rights, please review our Terms of Service (https://docs.github.com/en/site-policy/github-terms/github-terms-of-service) - https://docs.github.com/en/rest/using-the-rest-api/getting-started-with-the-rest-api#rate-limiting
• pull / nxp-build-test / linux-job (gh)
  ##[error]API rate limit exceeded for installation. If you reach out to GitHub Support for help, please include the request ID C2F8:3B7C4D:3A498F2:C5F4105:6A760B30 and timestamp 2026-08-07 16:43:28 UTC. For more on scraping GitHub and how it may affect your rights, please review our Terms of Service (https://docs.github.com/en/site-policy/github-terms/github-terms-of-service) - https://docs.github.com/en/rest/using-the-rest-api/getting-started-with-the-rest-api#rate-limiting
• pull / test-arm-backend-no-driver (test_pytest_models_tosa) / linux-job (gh)
  ##[error]An error occurred trying to start process '/usr/bin/bash' with working directory '/home/ec2-user/actions-runner/_work/executorch/executorch/pytorch/executorch'. No such file or directory
• pull / test-arm-backend-no-driver (test_pytest_ops_no_target) / linux-job (gh)
  ##[error]An error occurred trying to start process '/usr/bin/bash' with working directory '/home/ec2-user/actions-runner/_work/executorch/executorch/pytorch/executorch'. No such file or directory
• pull / test-arm-backend-no-driver (test_pytest_ops_tosa) / linux-job (gh)
  ##[error]API rate limit exceeded for installation. If you reach out to GitHub Support for help, please include the request ID B0C2:35B914:8386437:1BAC0CDB:6A760B70 and timestamp 2026-08-07 16:44:32 UTC. For more on scraping GitHub and how it may affect your rights, please review our Terms of Service (https://docs.github.com/en/site-policy/github-terms/github-terms-of-service) - https://docs.github.com/en/rest/using-the-rest-api/getting-started-with-the-rest-api#rate-limiting
• pull / test-arm-backend-no-driver (test_run_tosa) / linux-job (gh)
  ##[error]An error occurred trying to start process '/usr/bin/bash' with working directory '/home/ec2-user/actions-runner/_work/executorch/executorch/pytorch/executorch'. No such file or directory
• pull / test-arm-cortex-m-size-test (bare_metal) / linux-job (gh)
  ##[error]An error occurred trying to start process '/usr/bin/bash' with working directory '/home/ec2-user/actions-runner/_work/executorch/executorch/pytorch/executorch'. No such file or directory
• pull / test-arm-cortex-m-size-test (zephyr-preset) / linux-job (gh)
  ##[error]An error occurred trying to start process '/usr/bin/bash' with working directory '/home/ec2-user/actions-runner/_work/executorch/executorch/pytorch/executorch'. No such file or directory
• pull / test-binary-size-linux / linux-job (gh)
  ##[error]API rate limit exceeded for installation. If you reach out to GitHub Support for help, please include the request ID AC36:1B7A58:8D7B36A:1DAD9FA4:6A760B41 and timestamp 2026-08-07 16:43:45 UTC. For more on scraping GitHub and how it may affect your rights, please review our Terms of Service (https://docs.github.com/en/site-policy/github-terms/github-terms-of-service) - https://docs.github.com/en/rest/using-the-rest-api/getting-started-with-the-rest-api#rate-limiting
• pull / test-binary-size-linux-gcc / linux-job (gh)
  ##[error]API rate limit exceeded for installation. If you reach out to GitHub Support for help, please include the request ID 8386:16110:856A418:1BFD44B0:6A760B50 and timestamp 2026-08-07 16:44:00 UTC. For more on scraping GitHub and how it may affect your rights, please review our Terms of Service (https://docs.github.com/en/site-policy/github-terms/github-terms-of-service) - https://docs.github.com/en/rest/using-the-rest-api/getting-started-with-the-rest-api#rate-limiting
• pull / test-build-wasm-linux / linux-job (gh)
  ##[error]API rate limit exceeded for installation. If you reach out to GitHub Support for help, please include the request ID A038:3EBE49:88EA8C6:1CBDDF5C:6A760B7C and timestamp 2026-08-07 16:44:44 UTC. For more on scraping GitHub and how it may affect your rights, please review our Terms of Service (https://docs.github.com/en/site-policy/github-terms/github-terms-of-service) - https://docs.github.com/en/rest/using-the-rest-api/getting-started-with-the-rest-api#rate-limiting
• pull / test-custom-ops-linux / linux-job (gh)
  ##[error]API rate limit exceeded for installation. If you reach out to GitHub Support for help, please include the request ID BC14:23BD0:8FF1309:1E084786:6A760B59 and timestamp 2026-08-07 16:44:09 UTC. For more on scraping GitHub and how it may affect your rights, please review our Terms of Service (https://docs.github.com/en/site-policy/github-terms/github-terms-of-service) - https://docs.github.com/en/rest/using-the-rest-api/getting-started-with-the-rest-api#rate-limiting
• pull / test-llama-runner-linux-android / linux-job (gh)
  ##[error]API rate limit exceeded for installation. If you reach out to GitHub Support for help, please include the request ID 96C6:3440A9:3659E81:B8FECA6:6A760B35 and timestamp 2026-08-07 16:43:33 UTC. For more on scraping GitHub and how it may affect your rights, please review our Terms of Service (https://docs.github.com/en/site-policy/github-terms/github-terms-of-service) - https://docs.github.com/en/rest/using-the-rest-api/getting-started-with-the-rest-api#rate-limiting
• pull / test-llama-runner-qnn-linux (fp32, qnn_16a16w, qnn) / linux-job (gh)
  ##[error]API rate limit exceeded for installation. If you reach out to GitHub Support for help, please include the request ID CF2C:28EBC1:4A6667A:FC6BEA6:6A760B4B and timestamp 2026-08-07 16:43:55 UTC. For more on scraping GitHub and how it may affect your rights, please review our Terms of Service (https://docs.github.com/en/site-policy/github-terms/github-terms-of-service) - https://docs.github.com/en/rest/using-the-rest-api/getting-started-with-the-rest-api#rate-limiting
• pull / test-llama-runner-qnn-linux (fp32, qnn_8a8w, qnn) / linux-job (gh)
  ##[error]API rate limit exceeded for installation. If you reach out to GitHub Support for help, please include the request ID 907C:6D448:836E555:1BA4CB9F:6A760BA3 and timestamp 2026-08-07 16:45:23 UTC. For more on scraping GitHub and how it may affect your rights, please review our Terms of Service (https://docs.github.com/en/site-policy/github-terms/github-terms-of-service) - https://docs.github.com/en/rest/using-the-rest-api/getting-started-with-the-rest-api#rate-limiting
• pull / test-models-linux (add_mul, portable, linux.2xlarge) / linux-job (gh)
  ##[error]API rate limit exceeded for installation. If you reach out to GitHub Support for help, please include the request ID 9082:157945:881CDEE:1C9361CF:6A760B38 and timestamp 2026-08-07 16:43:36 UTC. For more on scraping GitHub and how it may affect your rights, please review our Terms of Service (https://docs.github.com/en/site-policy/github-terms/github-terms-of-service) - https://docs.github.com/en/rest/using-the-rest-api/getting-started-with-the-rest-api#rate-limiting
• pull / test-models-linux (add_mul, xnnpack-quantization-delegation, linux.2xlarge) / linux-job (gh)
  ##[error]API rate limit exceeded for installation. If you reach out to GitHub Support for help, please include the request ID B200:1B7A58:8D70AC8:1DAB6512:6A760B2D and timestamp 2026-08-07 16:43:25 UTC. For more on scraping GitHub and how it may affect your rights, please review our Terms of Service (https://docs.github.com/en/site-policy/github-terms/github-terms-of-service) - https://docs.github.com/en/rest/using-the-rest-api/getting-started-with-the-rest-api#rate-limiting
• pull / test-models-linux (emformer_transcribe, portable, linux.2xlarge) / linux-job (gh)
  ##[error]An error occurred trying to start process '/usr/bin/bash' with working directory '/home/ec2-user/actions-runner/_work/executorch/executorch/pytorch/executorch'. No such file or directory
• pull / test-models-linux (emformer_transcribe, xnnpack-quantization-delegation, linux.2xlarge) / linux-job (gh)
  ##[error]API rate limit exceeded for installation. If you reach out to GitHub Support for help, please include the request ID A786:34E3E2:896AD40:1CD028CC:6A760B3C and timestamp 2026-08-07 16:43:40 UTC. For more on scraping GitHub and how it may affect your rights, please review our Terms of Service (https://docs.github.com/en/site-policy/github-terms/github-terms-of-service) - https://docs.github.com/en/rest/using-the-rest-api/getting-started-with-the-rest-api#rate-limiting
• pull / test-moshi-linux / linux-job (gh)
  ##[error]An error occurred trying to start process '/usr/bin/bash' with working directory '/home/ec2-user/actions-runner/_work/executorch/executorch/pytorch/executorch'. No such file or directory
• pull / test-multimodal-linux (gemma3-4b) / linux-job (gh)
  ##[error]API rate limit exceeded for installation. If you reach out to GitHub Support for help, please include the request ID E4B0:37D8D8:816B803:1B3DAF19:6A760B50 and timestamp 2026-08-07 16:44:00 UTC. For more on scraping GitHub and how it may affect your rights, please review our Terms of Service (https://docs.github.com/en/site-policy/github-terms/github-terms-of-service) - https://docs.github.com/en/rest/using-the-rest-api/getting-started-with-the-rest-api#rate-limiting
• pull / test-openvino-linux / linux-job (gh)
  ##[error]API rate limit exceeded for installation. If you reach out to GitHub Support for help, please include the request ID CC1E:2FFF42:4C7A070:102D352D:6A760B5E and timestamp 2026-08-07 16:44:14 UTC. For more on scraping GitHub and how it may affect your rights, please review our Terms of Service (https://docs.github.com/en/site-policy/github-terms/github-terms-of-service) - https://docs.github.com/en/rest/using-the-rest-api/getting-started-with-the-rest-api#rate-limiting
• pull / test-parakeet-xnnpack-linux / linux-job (gh)
  ##[error]An error occurred trying to start process '/usr/bin/bash' with working directory '/home/ec2-user/actions-runner/_work/executorch/executorch/pytorch/executorch'. No such file or directory
• pull / test-qnn-buck-build-linux / linux-job (gh)
  ##[error]An error occurred trying to start process '/usr/bin/bash' with working directory '/home/ec2-user/actions-runner/_work/executorch/executorch/pytorch/executorch'. No such file or directory
• pull / test-qnn-delegate-linux / linux-job (gh)
  ##[error]An error occurred trying to start process '/usr/bin/bash' with working directory '/home/ec2-user/actions-runner/_work/executorch/executorch/pytorch/executorch'. No such file or directory
• pull / test-qnn-models-linux (dl3) / linux-job (gh)
  ##[error]API rate limit exceeded for installation. If you reach out to GitHub Support for help, please include the request ID E104:1677CB:8843434:1C771284:6A760B71 and timestamp 2026-08-07 16:44:33 UTC. For more on scraping GitHub and how it may affect your rights, please review our Terms of Service (https://docs.github.com/en/site-policy/github-terms/github-terms-of-service) - https://docs.github.com/en/rest/using-the-rest-api/getting-started-with-the-rest-api#rate-limiting
• pull / test-qnn-models-linux (mv2) / linux-job (gh)
  ##[error]API rate limit exceeded for installation. If you reach out to GitHub Support for help, please include the request ID EB04:236993:4FD290F:10DC62D0:6A760B58 and timestamp 2026-08-07 16:44:08 UTC. For more on scraping GitHub and how it may affect your rights, please review our Terms of Service (https://docs.github.com/en/site-policy/github-terms/github-terms-of-service) - https://docs.github.com/en/rest/using-the-rest-api/getting-started-with-the-rest-api#rate-limiting
• pull / test-qnn-models-linux (mv3) / linux-job (gh)
  ##[error]API rate limit exceeded for installation. If you reach out to GitHub Support for help, please include the request ID D014:37AD1A:81E0E79:1B44D8C9:6A760B6C and timestamp 2026-08-07 16:44:28 UTC. For more on scraping GitHub and how it may affect your rights, please review our Terms of Service (https://docs.github.com/en/site-policy/github-terms/github-terms-of-service) - https://docs.github.com/en/rest/using-the-rest-api/getting-started-with-the-rest-api#rate-limiting
• pull / test-qnn-passes-linux / linux-job (gh)
  ##[error]An error occurred trying to start process '/usr/bin/bash' with working directory '/home/ec2-user/actions-runner/_work/executorch/executorch/pytorch/executorch'. No such file or directory
• pull / test-qnn-python-imports-linux / linux-job (gh)
  ##[error]An error occurred trying to start process '/usr/bin/bash' with working directory '/home/ec2-user/actions-runner/_work/executorch/executorch/pytorch/executorch'. No such file or directory
• pull / test-qnn-testsuite-linux / test-backend-linux (qnn, models) / linux-job (gh)
  ##[error]API rate limit exceeded for installation. If you reach out to GitHub Support for help, please include the request ID B37A:3BCE59:87CECF9:1C826177:6A760BA5 and timestamp 2026-08-07 16:45:25 UTC. For more on scraping GitHub and how it may affect your rights, please review our Terms of Service (https://docs.github.com/en/site-policy/github-terms/github-terms-of-service) - https://docs.github.com/en/rest/using-the-rest-api/getting-started-with-the-rest-api#rate-limiting
• pull / test-qnn-testsuite-linux / test-backend-linux (qnn, operators) / linux-job (gh)
  ##[error]API rate limit exceeded for installation. If you reach out to GitHub Support for help, please include the request ID DDB6:333A82:89D96AD:1CF19CF3:6A760BA2 and timestamp 2026-08-07 16:45:22 UTC. For more on scraping GitHub and how it may affect your rights, please review our Terms of Service (https://docs.github.com/en/site-policy/github-terms/github-terms-of-service) - https://docs.github.com/en/rest/using-the-rest-api/getting-started-with-the-rest-api#rate-limiting
• pull / test-quantized-aot-lib-linux / linux-job (gh)
  ##[error]API rate limit exceeded for installation. If you reach out to GitHub Support for help, please include the request ID D666:1BBE8E:4BF7C86:10133460:6A760B3A and timestamp 2026-08-07 16:43:38 UTC. For more on scraping GitHub and how it may affect your rights, please review our Terms of Service (https://docs.github.com/en/site-policy/github-terms/github-terms-of-service) - https://docs.github.com/en/rest/using-the-rest-api/getting-started-with-the-rest-api#rate-limiting
• pull / test-samsung-quantmodels-linux / linux-job (gh)
  ##[error]API rate limit exceeded for installation. If you reach out to GitHub Support for help, please include the request ID ECF4:AD45:36D9D79:BADF972:6A760B35 and timestamp 2026-08-07 16:43:33 UTC. For more on scraping GitHub and how it may affect your rights, please review our Terms of Service (https://docs.github.com/en/site-policy/github-terms/github-terms-of-service) - https://docs.github.com/en/rest/using-the-rest-api/getting-started-with-the-rest-api#rate-limiting
• pull / test-selective-build-linux / linux-job (gh)
  ##[error]API rate limit exceeded for installation. If you reach out to GitHub Support for help, please include the request ID A24C:10292D:36D7688:BA68682:6A760B45 and timestamp 2026-08-07 16:43:49 UTC. For more on scraping GitHub and how it may affect your rights, please review our Terms of Service (https://docs.github.com/en/site-policy/github-terms/github-terms-of-service) - https://docs.github.com/en/rest/using-the-rest-api/getting-started-with-the-rest-api#rate-limiting
• pull / test-sqnr-static-llm-qnn-linux (smollm2_135m) / linux-job (gh)
  ##[error]An error occurred trying to start process '/usr/bin/bash' with working directory '/home/ec2-user/actions-runner/_work/executorch/executorch/pytorch/executorch'. No such file or directory
• pull / test-static-llama-qnn-linux (stories_110m) / linux-job (gh)
  ##[error]An error occurred trying to start process '/usr/bin/bash' with working directory '/home/ec2-user/actions-runner/_work/executorch/executorch/pytorch/executorch'. No such file or directory
• pull / test-static-llama-qnn-linux (stories_260k_bc) / linux-job (gh)
  ##[error]API rate limit exceeded for installation. If you reach out to GitHub Support for help, please include the request ID E988:37D8D8:8168028:1B3CF23C:6A760B48 and timestamp 2026-08-07 16:43:52 UTC. For more on scraping GitHub and how it may affect your rights, please review our Terms of Service (https://docs.github.com/en/site-policy/github-terms/github-terms-of-service) - https://docs.github.com/en/rest/using-the-rest-api/getting-started-with-the-rest-api#rate-limiting
• pull / unittest-wasm-bindings (--enable-etdump) / linux-job (gh)
  ##[error]API rate limit exceeded for installation. If you reach out to GitHub Support for help, please include the request ID B7E4:37837C:830B2B9:1B7EEAF2:6A760B98 and timestamp 2026-08-07 16:45:12 UTC. For more on scraping GitHub and how it may affect your rights, please review our Terms of Service (https://docs.github.com/en/site-policy/github-terms/github-terms-of-service) - https://docs.github.com/en/rest/using-the-rest-api/getting-started-with-the-rest-api#rate-limiting

This comment was automatically generated by Dr. CI and updates every 15 minutes.

[github-actions]

This PR needs a release notes: label

If your change should be included in the release notes (i.e. would users of this library care about this change?), please use a label starting with release notes:. This helps us keep track and include your important work in the next release notes.

To add a label, you can comment to pytorchbot, for example
@pytorchbot label "release notes: none"

For more information, see
https://github.com/pytorch/pytorch/wiki/PyTorch-AutoLabel-Bot#why-categorize-for-release-notes-and-how-does-it-work.