FSDP sharding_strategy parameter fails with KeyError when passed as string

[junuMoon]

System Info

PyTorch version: 2.1.0
Python version: 3.10
OS: Ubuntu 22.04

Information

• The official example scripts
• My own modified scripts

🐛 Describe the bug

When passing sharding_strategy as a command line argument to FSDP config, it fails with a KeyError because the string value is not properly converted to ShardingStrategy enum.

Running with --fsdp_config.sharding_strategy "FULL_SHARD" results in:

KeyError: 'FULL_SHARD'

Error logs

Traceback (most recent call last):
  File "finetuning.py", line 272, in main
    model = FSDP(
  ...
  File "torch/distributed/fsdp/_init_utils.py", line 652, in _init_param_handle_from_params
    SHARDING_STRATEGY_MAP[state.sharding_strategy],
KeyError: 'FULL_SHARD'

Expected behavior

The string value "FULL_SHARD" should be converted to ShardingStrategy.FULL_SHARD enum when updating the config.

[vz-2244]

Same issue here. Any suggestion about how to change the FSDP config from command line?