fix nccl pg destroy warning

src/axolotl/train.py

@@ -27,6 +27,7 @@ from axolotl.contribs.lgpl import (  # pylint: disable = no-name-in-module
 from axolotl.core.trainer_builder import HFCausalTrainerBuilder, HFRLTrainerBuilder
 from axolotl.logging_config import configure_logging
 from axolotl.utils.dict import DictDefault
+from axolotl.utils.distributed import cleanup_distributed
 from axolotl.utils.freeze import freeze_layers_except
 from axolotl.utils.models import load_model, load_processor, load_tokenizer
 from axolotl.utils.trainer import setup_trainer
@@ -157,6 +158,8 @@ def setup_signal_handler(
                 _model.save_pretrained(
                     cfg.output_dir, safe_serialization=safe_serialization
                 )
+
+            cleanup_distributed()
             sys.exit(0)
 
         _model_weakref = weakref.ref(model)
@@ -478,7 +481,7 @@ def train(
     Returns:
         Tuple of (model, tokenizer) after training
     """
-    # Setup model, tokenizer, (causal or RLHF) trainer etc.
+    # Setup model, tokenizer, (causal or RLHF) trainer, etc.
     (
         trainer,
         model,
@@ -487,34 +490,25 @@ def train(
         processor,
     ) = setup_model_and_trainer(cfg, dataset_meta)
 
-    # Determine if we need to resume from a checkpoint
-    resume_from_checkpoint = determine_resume_checkpoint(cfg)
-
-    # Configuration for saving
-    safe_serialization = cfg.save_safetensors is True
-
     # Handle untrained tokens if configured
+    safe_serialization = cfg.save_safetensors is True
     train_dataset = dataset_meta.train_dataset
     handle_untrained_tokens_fix(
         cfg, model, tokenizer, train_dataset, safe_serialization
     )
 
-    # Save initial configs
+    # Additional setup
     save_initial_configs(cfg, tokenizer, model, peft_config, processor)
-
-    # Set up signal handler for graceful termination
     setup_signal_handler(cfg, model, safe_serialization)
-
-    # Set up badges and config info for model card
     setup_model_card(cfg)
 
     # Execute the training
+    resume_from_checkpoint = determine_resume_checkpoint(cfg)
     execute_training(cfg, trainer, resume_from_checkpoint)
 
-    # Save the trained model
+    # Save the trained model and cleanup
     save_trained_model(cfg, trainer, model, safe_serialization)
-
-    # Create model card
     create_model_card(cfg, trainer)
+    cleanup_distributed()
 
     return model, tokenizer, trainer

src/axolotl/utils/distributed.py

@@ -71,8 +71,8 @@ def barrier():
 
 def is_main_process():
     """
-    Check if the current process is the main process.
-    If not in distributed mode, always return True.
+    Check if the current process is the main process. If not in distributed mode,
+    always return `True`.
     """
     if not is_distributed():
         return True
@@ -87,6 +87,18 @@ def get_world_size():
     return int(os.getenv("WORLD_SIZE", "1"))
 
 
+def cleanup_distributed():
+    """
+    Destroy process group if torch distributed is initialized. Called in training early
+    termination or when training successfully completes.
+    """
+    # Ensure that all operations are completed before destroying the process group
+    torch.cuda.synchronize()
+    # Destroy the process group
+    if torch.distributed.is_initialized():
+        torch.distributed.destroy_process_group()
+
+
 @contextmanager
 def zero_only():
     """