[fix] Fix the pretty trainer logging

skyrl-train/skyrl_train/trainer.py

@@ -56,6 +56,7 @@
     ResumeMode,
     DynamicSamplingState,
 )
+from skyrl_train.utils.utils import configure_ray_worker_logging
 
 
 class RayPPOTrainer:
@@ -100,6 +101,7 @@ def __init__(
         self.dynamic_sampling_state: Optional[DynamicSamplingState] = None
 
         self.reward_kl_controller: Optional[Union[FixedKLController, AdaptiveKLController]] = None
+        configure_ray_worker_logging()
 
     def build_dataloader(self, dataset: PromptDataset, is_train=True):
         """

skyrl-train/skyrl_train/utils/utils.py

@@ -1,6 +1,7 @@
 import os
 import time
-
+import sys
+import logging
 import ray
 import torch
 from loguru import logger
@@ -465,6 +466,43 @@ def prepare_runtime_environment(cfg: DictConfig) -> dict[str, str]:
     return env_vars
 
 
+def configure_ray_worker_logging() -> None:
+    """
+    In Ray workers, stderr/stdout are not TTYs, so Loguru disables color.
+    `configure_worker_logging` is used within each Ray worker to
+    force color and formatting (e.g., bold) and route stdlib `logging`
+    through Loguru so third‑party logs match formatting
+    """
+    # 1) Loguru formatting (force colors)
+    logger.remove()
+    logger.level("INFO", color="<bold><green>")
+    logger.add(
+        sys.stderr,
+        colorize=True,  # keep ANSI even without a TTY
+        enqueue=True,
+        backtrace=False,
+        diagnose=False,
+        format="<green>{time:YYYY-MM-DD HH:mm:ss.SSS}</green> | "
+        "<level>{level: <8}</level> | "
+        "<cyan>{name}</cyan>:<cyan>{function}</cyan>:<cyan>{line}</cyan> - "
+        "<level>{message}</level>",
+    )
+
+    # 2) Route stdlib logging -> Loguru (so vLLM/transformers/etc. are formatted)
+    class _InterceptHandler(logging.Handler):
+        def emit(self, record: logging.LogRecord) -> None:
+            try:
+                level = logger.level(record.levelname).name
+            except ValueError:
+                level = record.levelno
+            logger.opt(depth=6, exception=record.exc_info).log(level, record.getMessage())
+
+    logging.root.handlers = [_InterceptHandler()]
+    level_name = os.getenv("LOG_LEVEL", "INFO").upper()
+    level = getattr(logging, level_name, logging.INFO)
+    logging.root.setLevel(level)
+
+
 def initialize_ray(cfg: DictConfig):
     """
     Initialize Ray cluster with prepared runtime environment.