Fix fp16 NaN flake in spec CI: bf16 eagle fixture; sanitize NaN logits in sampler (#27883)

python/sglang/srt/layers/sampler.py

@@ -16,6 +16,7 @@ from sglang.srt.layers.utils.logprob import get_token_ids_logprobs, get_top_logp
 from sglang.srt.sampling.sampling_batch_info import SamplingBatchInfo
 from sglang.srt.sampling.sampling_params import TOP_K_ALL
 from sglang.srt.server_args import get_global_server_args
+from sglang.srt.utils.async_probe import sanitize_nan_logits
 from sglang.srt.utils.common import (
     get_bool_env_var,
     is_cuda,
@@ -83,9 +84,10 @@ class Sampler(nn.Module):
     def _preprocess_logits(
         self, logits: torch.Tensor, sampling_info: SamplingBatchInfo
     ) -> torch.Tensor:
-        """Apply custom logit processors."""
+        """Apply custom logit processors and sanitize non-finite logits."""
         if sampling_info.has_custom_logit_processor:
             apply_custom_logit_processor(logits, sampling_info)
+        sanitize_nan_logits(logits, "sampler: next_token_logits")
         return logits
 
     def forward(