{"record":{"id":"237461a1c526063d","repo":"sgl-project/sglang","slug":"sana-video-checkpoints-with-embedded-guidance-are","errorCode":null,"errorMessage":"SANA-Video checkpoints with embedded guidance are not supported","messagePattern":"SANA-Video checkpoints with embedded guidance are not supported","errorType":"validation","errorClass":"NotImplementedError","httpStatus":null,"severity":"error","filePath":"python/sglang/multimodal_gen/runtime/models/dits/sana_video.py","lineNumber":472,"sourceCode":"        self.patch_size = tuple(arch.patch_size)\n        self.inner_dim = arch.num_attention_heads * arch.attention_head_dim\n        self.hidden_size = self.inner_dim\n        self.num_attention_heads = arch.num_attention_heads\n        self.num_channels_latents = arch.num_channels_latents\n        self.caption_channels = arch.caption_channels\n        self.cross_attention_dim = arch.cross_attention_dim\n\n        self.rope = SanaVideoRotaryPosEmbed(\n            arch.attention_head_dim, self.patch_size, arch.rope_max_seq_len\n        )\n        self.patch_embedding = nn.Conv3d(\n            arch.in_channels,\n            self.inner_dim,\n            kernel_size=self.patch_size,\n            stride=self.patch_size,\n        )\n        if arch.guidance_embeds:\n            raise NotImplementedError(\n                \"SANA-Video checkpoints with embedded guidance are not supported\"\n            )\n        self.time_embed = SanaAdaLayerNormSingle(self.inner_dim)\n        self.caption_projection = PixArtAlphaTextProjection(\n            in_features=arch.caption_channels, hidden_size=self.inner_dim\n        )\n        self.caption_norm = RMSNorm(self.inner_dim, eps=1e-5)\n        self.transformer_blocks = nn.ModuleList(\n            [\n                SanaVideoTransformerBlock(\n                    dim=self.inner_dim,\n                    num_attention_heads=arch.num_attention_heads,\n                    attention_head_dim=arch.attention_head_dim,\n                    num_cross_attention_heads=arch.num_cross_attention_heads,\n                    cross_attention_head_dim=arch.cross_attention_head_dim,\n                    cross_attention_dim=arch.cross_attention_dim,\n                    mlp_ratio=arch.mlp_ratio,\n                    norm_eps=arch.norm_eps,","sourceCodeStart":454,"sourceCodeEnd":490,"githubUrl":"https://github.com/sgl-project/sglang/blob/0132848349585cfe6aae51c4941cbae872505f8a/python/sglang/multimodal_gen/runtime/models/dits/sana_video.py#L454-L490","documentation":"SANA-Video raises NotImplementedError at construction when the checkpoint config has guidance_embeds enabled — this implementation has no guidance-embedding pathway, so such checkpoints are explicitly rejected rather than silently misbehaving.","triggerScenarios":"Loading a SANA-Video checkpoint whose arch config sets guidance_embeds=True (guidance-distilled variant).","commonSituations":"Pointing the loader at a newer guidance-distilled SANA-Video release; config JSON copied from the wrong variant on the hub.","solutions":["Use a non-guidance-embed SANA-Video checkpoint (guidance_embeds false/absent in config)","Or pass guidance via the API instead of an embedded-guidance checkpoint","Wait for/update to a library version implementing guidance_embeds"],"exampleFix":"# before: config.json has \"guidance_embeds\": true\nmodel = SanaVideoModel.from_pretrained(distilled_ckpt)\n# after: choose base variant\nmodel = SanaVideoModel.from_pretrained(base_ckpt)","handlingStrategy":"validation","validationCode":"assert not arch.guidance_embeds, \"SANA-Video guidance-embed checkpoints unsupported; use the base variant\"","typeGuard":"def is_supported_sana_video_checkpoint(arch) -> bool:\n    return not getattr(arch, \"guidance_embeds\", False)","tryCatchPattern":null,"preventionTips":["Check config.json's guidance_embeds before from_pretrained","Pin known-good checkpoint revisions"],"tags":["sana-video","guidance-embeds","unsupported-checkpoint"],"backgroundTag":"unsupported-configuration-value","analyzedSha":"0132848349585cfe6aae51c4941cbae872505f8a","analyzedAt":"2026-08-28T05:10:05.995Z","schemaVersion":2},"datasetVersion":"2026-08-28T06:17:29.519Z"}