{"record":{"id":"da9c9dc1f56c4cc2","repo":"sgl-project/sglang","slug":"unsupported-activation-hidden-act-arcee-model","errorCode":null,"errorMessage":"Unsupported activation: {hidden_act}. Arcee model in SGLang only supports 'relu2'.","messagePattern":"Unsupported activation: (.+?)\\. Arcee model in SGLang only supports 'relu2'\\.","errorType":"exception","errorClass":"ValueError","httpStatus":null,"severity":"critical","filePath":"python/sglang/srt/models/arcee.py","lineNumber":88,"sourceCode":"        super().__init__()\n        # Arcee uses a single up-projection, not a merged gate/up projection.\n        self.up_proj = ColumnParallelLinear(\n            hidden_size,\n            intermediate_size,\n            bias=False,\n            quant_config=quant_config,\n            prefix=add_prefix(\"up_proj\", prefix),\n        )\n        self.down_proj = RowParallelLinear(\n            intermediate_size,\n            hidden_size,\n            bias=False,\n            quant_config=quant_config,\n            prefix=add_prefix(\"down_proj\", prefix),\n            reduce_results=reduce_results,\n        )\n        if hidden_act != \"relu2\":\n            raise ValueError(\n                f\"Unsupported activation: {hidden_act}. \"\n                \"Arcee model in SGLang only supports 'relu2'.\"\n            )\n        # The activation function is relu(x)^2\n        self.act_fn = get_act_fn(\"relu2\")\n\n    def forward(self, x, forward_batch=None):\n        x, _ = self.up_proj(x)\n        x = self.act_fn(x)\n        x, _ = self.down_proj(x)\n        return x\n\n\nclass ArceeAttention(nn.Module):\n    def __init__(\n        self,\n        config: LlamaConfig,\n        hidden_size: int,","sourceCodeStart":70,"sourceCodeEnd":106,"githubUrl":"https://github.com/sgl-project/sglang/blob/0132848349585cfe6aae51c4941cbae872505f8a/python/sglang/srt/models/arcee.py#L70-L106","documentation":"The Arcee MLP implementation only supports the squared-ReLU ('relu2') activation; the config's hidden_act must be exactly 'relu2'.","triggerScenarios":"Loading an Arcee checkpoint whose config.json hidden_act is not \"relu2\" (e.g. \"gelu\" or \"silu\").","commonSituations":"Fine-tunes or converted checkpoints with a different activation; typo or default value written by a conversion script.","solutions":["Set \"hidden_act\": \"relu2\" in the model's config.json","Use an original Arcee checkpoint that ships relu2"],"exampleFix":"// before\n\"hidden_act\": \"gelu\"\n// after\n\"hidden_act\": \"relu2\"","handlingStrategy":"validation","validationCode":"assert config.hidden_act == \"relu2\"","typeGuard":null,"tryCatchPattern":null,"preventionTips":["Pin configs of Arcee checkpoints to relu2"],"tags":["activation","config-validation","arcee"],"backgroundTag":"unsupported-activation-function","analyzedSha":"0132848349585cfe6aae51c4941cbae872505f8a","analyzedAt":"2026-08-28T05:10:05.995Z","schemaVersion":2},"datasetVersion":"2026-08-28T06:17:29.519Z"}