[ci] Repair fastcheck contract drift

docs/design/inference_schema_parity_inventory.yaml

@@ -119,12 +119,14 @@ surfaces:
       vae_precision: "Precision override pending dedicated typed component precision design."
       vae_decode_precision: "Decode-only precision override pending dedicated typed component precision design."
       image_encoder_precision: "Precision override pending dedicated typed component precision design."
+      image_encoder_precisions: "Multi-encoder precision overrides pending dedicated typed component precision design."
       text_encoder_precisions: "Precision override pending dedicated typed component precision design."
     internal_only:
       dit_config: "Legacy internal component config object."
       upsampler_config: "Legacy internal component config object."
       vae_config: "Legacy internal component config object."
       image_encoder_config: "Legacy internal component config object."
+      image_encoder_configs: "Legacy internal multi-encoder component config objects."
       text_encoder_configs: "Legacy internal component config object."
       preprocess_text_funcs: "Internal text preprocessing hooks."
       postprocess_text_funcs: "Internal text postprocessing hooks."
@@ -375,6 +377,7 @@ surfaces:
           - fastvideo.configs.pipelines.stable_audio.StableAudioOpenSmallConfig
       max_audio_duration_s:
         sources:
+          - fastvideo.configs.pipelines.mmaudio.MMAudioV2AConfig
           - fastvideo.configs.pipelines.stable_audio.StableAudioT2AConfig
           - fastvideo.configs.pipelines.stable_audio.StableAudioOpenSmallConfig
       sample_size:
@@ -383,8 +386,33 @@ surfaces:
           - fastvideo.configs.pipelines.stable_audio.StableAudioOpenSmallConfig
       sampling_rate:
         sources:
+          - fastvideo.configs.pipelines.mmaudio.MMAudioV2AConfig
           - fastvideo.configs.pipelines.stable_audio.StableAudioT2AConfig
           - fastvideo.configs.pipelines.stable_audio.StableAudioOpenSmallConfig
+      duration_s:
+        sources: [fastvideo.configs.pipelines.mmaudio.MMAudioV2AConfig]
+      spectrogram_frame_rate:
+        sources: [fastvideo.configs.pipelines.mmaudio.MMAudioV2AConfig]
+      latent_downsample_rate:
+        sources: [fastvideo.configs.pipelines.mmaudio.MMAudioV2AConfig]
+      clip_frame_rate:
+        sources: [fastvideo.configs.pipelines.mmaudio.MMAudioV2AConfig]
+      sync_frame_rate:
+        sources: [fastvideo.configs.pipelines.mmaudio.MMAudioV2AConfig]
+      sync_segment_size:
+        sources: [fastvideo.configs.pipelines.mmaudio.MMAudioV2AConfig]
+      sync_segment_stride:
+        sources: [fastvideo.configs.pipelines.mmaudio.MMAudioV2AConfig]
+      sync_downsample_rate:
+        sources: [fastvideo.configs.pipelines.mmaudio.MMAudioV2AConfig]
+      clip_image_size:
+        sources: [fastvideo.configs.pipelines.mmaudio.MMAudioV2AConfig]
+      sync_image_size:
+        sources: [fastvideo.configs.pipelines.mmaudio.MMAudioV2AConfig]
+      clip_batch_size_multiplier:
+        sources: [fastvideo.configs.pipelines.mmaudio.MMAudioV2AConfig]
+      sync_batch_size_multiplier:
+        sources: [fastvideo.configs.pipelines.mmaudio.MMAudioV2AConfig]
       audio_txt_guidance_scale:
         sources: [fastvideo.pipelines.basic.magi_human.pipeline_configs.MagiHumanBaseConfig]
       cfg_number:

fastvideo/tests/api/test_attn_qat_infer_capability_gate.py

@@ -5,10 +5,9 @@
 ``is_attn_qat_infer_available()`` used to test only whether the kernel
 extension imports. CUDA 13 wheel builds can carry the sm_120/sm_121
 extension on any host (e.g. H100 sm_90, GB200 sm_100): the import
-succeeds, ``CudaPlatformBase.get_attn_backend_cls`` selects the
-consumer-Blackwell backend, and the first kernel call fails with an
-unsupported-capability error -- instead of the FlashAttention fallback
-the QAD README documents for non-sm_120 GPUs.
+succeeds, ``CudaPlatformBase.get_attn_backend_cls`` must reject the explicitly
+selected backend before the first kernel call can fail with an opaque
+unsupported-capability error.
 
 These tests drive the REAL resolver (``fastvideo.platforms.cuda``) and
 the REAL availability function; only the two physical facts are faked --
@@ -17,8 +16,8 @@
 (fastvideo/tests/stages/test_kandinsky5_attention_backend_guard.py)
 injects an already-resolved backend and by design cannot see this bug.
 
-CPU-only: the ATTN_QAT_INFER branch and its fallback never require a
-physical GPU to *resolve* (only to run).
+CPU-only: the ATTN_QAT_INFER branch does not require a physical GPU to
+*resolve* (only to run).
 """
 from __future__ import annotations
 
@@ -35,15 +34,6 @@
 from fastvideo.platforms.interface import AttentionBackendEnum
 
 ATTN_QAT_INFER_CLS = "fastvideo.attention.backends.attn_qat_infer.AttnQatInferBackend"
-# What the resolver's fallthrough legitimately returns when ATTN_QAT_INFER
-# is unavailable: FlashAttention, or SDPA when flash_attn isn't installed
-# in the running environment (e.g. CPU-only CI).
-FALLBACK_CLASSES = {
-    "fastvideo.attention.backends.flash_attn.FlashAttentionBackend",
-    "fastvideo.attention.backends.sdpa.SDPABackend",
-}
-
-
 def _fake_gpu(monkeypatch, *, capability: tuple[int, int], extension_imports: bool, fa4_imports: bool = False) -> None:
     monkeypatch.setattr(torch.cuda, "is_available", lambda: True)
     monkeypatch.setattr(torch.cuda, "get_device_capability", lambda device=None: capability)
@@ -66,22 +56,27 @@ def _resolve() -> str:
     )
 
 
-def test_sm90_host_with_bundled_extension_falls_back(monkeypatch):
+def _assert_unavailable_backend_is_rejected() -> None:
+    with pytest.raises(ImportError, match="ATTN_QAT_INFER selected.*not usable"):
+        _resolve()
+
+
+def test_sm90_host_with_bundled_extension_is_rejected(monkeypatch):
     """The reviewed failure: H100 + CUDA 13 wheel that bundles the sm_120
-    extension. Import succeeds; selection must still fall back."""
+    extension. Import succeeds; explicit selection must still be rejected."""
     _fake_gpu(monkeypatch, capability=(9, 0), extension_imports=True)
 
     assert not is_attn_qat_infer_available()
-    assert _resolve() in FALLBACK_CLASSES
+    _assert_unavailable_backend_is_rejected()
 
 
-def test_sm100_host_with_bundled_extension_falls_back(monkeypatch):
+def test_sm100_host_with_bundled_extension_is_rejected(monkeypatch):
     """sm_100 with only the (unrunnable) bundled sm_12x extension and no
-    FP4 FA4 kernel still falls back -- the original reviewed failure class."""
+    FP4 FA4 kernel is rejected -- the original reviewed failure class."""
     _fake_gpu(monkeypatch, capability=(10, 0), extension_imports=True, fa4_imports=False)
 
     assert not is_attn_qat_infer_available()
-    assert _resolve() in FALLBACK_CLASSES
+    _assert_unavailable_backend_is_rejected()
 
 
 @pytest.mark.parametrize("capability", [(10, 0), (10, 3)])
@@ -102,11 +97,11 @@ def test_consumer_blackwell_with_extension_selects_backend(monkeypatch, capabili
     assert _resolve() == ATTN_QAT_INFER_CLS
 
 
-def test_consumer_blackwell_without_extension_falls_back(monkeypatch):
+def test_consumer_blackwell_without_extension_is_rejected(monkeypatch):
     _fake_gpu(monkeypatch, capability=(12, 0), extension_imports=False)
 
     assert not is_attn_qat_infer_available()
-    assert _resolve() in FALLBACK_CLASSES
+    _assert_unavailable_backend_is_rejected()
 
 
 def test_no_cuda_reports_unavailable(monkeypatch):

fastvideo/tests/contract/test_ci_test_collection.py

@@ -34,6 +34,7 @@
     "distributed": "no lane yet — multi-GPU torchrun tests, run manually",
     "hooks": "no lane yet — run manually",
     "layers": "no lane yet — torchrun FSDP dispatch tests, run manually",
+    "mlx": "Apple Silicon/Metal-specific suite; the Modal PR lanes run on Linux CUDA",
     "nightly": "by design: nightly cadence, not per-PR",
     "modal": "CI infrastructure itself, not a test suite",
 }

fastvideo/tests/contract/test_modal_fa4_policy.py

@@ -26,14 +26,28 @@ def _function_strings(path: Path, function_name: str) -> str:
     raise AssertionError(f"{function_name} not found in {path}")
 
 
+def _image_env_default(path: Path, env_name: str) -> str:
+    tree = ast.parse(path.read_text(encoding="utf-8"))
+    for node in ast.walk(tree):
+        if not isinstance(node, ast.Dict):
+            continue
+        for key, value in zip(node.keys, node.values, strict=True):
+            if not (isinstance(key, ast.Constant) and key.value == env_name):
+                continue
+            if (isinstance(value, ast.Call) and isinstance(value.func, ast.Attribute)
+                    and value.func.attr == "get" and len(value.args) == 2
+                    and isinstance(value.args[0], ast.Constant) and value.args[0].value == env_name
+                    and isinstance(value.args[1], ast.Constant) and isinstance(value.args[1].value, str)):
+                return value.args[1].value
+    raise AssertionError(f"{env_name} default not found in an image environment dictionary in {path}")
+
+
 def test_generic_l40s_launcher_defaults_fa4_off():
-    source = LAUNCH_L40S_JOB.read_text(encoding="utf-8")
-    assert '"FASTVIDEO_FA4": os.environ.get("FASTVIDEO_FA4", "0")' in source
+    assert _image_env_default(LAUNCH_L40S_JOB, "FASTVIDEO_FA4") == "0"
 
 
 def test_ssim_launcher_keeps_fa4_enabled_by_default():
-    source = SSIM_TEST.read_text(encoding="utf-8")
-    assert '"FASTVIDEO_FA4": os.environ.get("FASTVIDEO_FA4", "1")' in source
+    assert _image_env_default(SSIM_TEST, "FASTVIDEO_FA4") == "1"
 
 
 def test_performance_identity_env_reaches_modal_runtime():

fastvideo/tests/modal/pr_test.py

@@ -352,6 +352,7 @@ def run_unit_test():
     run_test("pytest ./fastvideo/tests/api/ ./fastvideo/tests/contract/ ./fastvideo/tests/dataset/ "
              "./fastvideo/tests/workflow/ ./fastvideo/tests/entrypoints/ ./fastvideo/tests/train/ "
              "./fastvideo/tests/stages/ ./fastvideo/tests/ops/ ./fastvideo/tests/worker/ "
+             "./fastvideo/tests/platforms/ "
              "./fastvideo/tests/training/test_trackers.py "
              "./fastvideo/tests/attention/test_sdpa_metadata_mask_contract.py "
              "./fastvideo/tests/modal/test_kernel_build_cache.py ./fastvideo/tests/modal/test_pr_test.py "