[Fix] Fix accepting an unexpected argument local-rank in PyTorch 2.0 (open-mmlab#2812)

Author: xiexinch

tools/test.py

@@ -47,7 +47,10 @@ def parse_args():
         help='job launcher')
     parser.add_argument(
         '--tta', action='store_true', help='Test time augmentation')
-    parser.add_argument('--local_rank', type=int, default=0)
+    # When using PyTorch version >= 2.0.0, the `torch.distributed.launch`
+    # will pass the `--local-rank` parameter to `tools/train.py` instead
+    # of `--local_rank`.
+    parser.add_argument('--local_rank', '--local-rank', type=int, default=0)
     args = parser.parse_args()
     if 'LOCAL_RANK' not in os.environ:
         os.environ['LOCAL_RANK'] = str(args.local_rank)

tools/train.py

@@ -40,7 +40,10 @@ def parse_args():
         choices=['none', 'pytorch', 'slurm', 'mpi'],
         default='none',
         help='job launcher')
-    parser.add_argument('--local_rank', type=int, default=0)
+    # When using PyTorch version >= 2.0.0, the `torch.distributed.launch`
+    # will pass the `--local-rank` parameter to `tools/train.py` instead
+    # of `--local_rank`.
+    parser.add_argument('--local_rank', '--local-rank', type=int, default=0)
     args = parser.parse_args()
     if 'LOCAL_RANK' not in os.environ:
         os.environ['LOCAL_RANK'] = str(args.local_rank)