lora qwen-image, error: The IPv6 network addresses of (I, 38455) cannot be retrieved (gai error: -2 - Name or service not known).

nohup: ignoring input
The following values were not passed to accelerate launch and had defaults used instead:
--num_processes was set to a value of 2
More than one GPU was found, enabling multi-GPU training.
If this was unintended please pass in --num_processes=1.
--num_machines was set to a value of 1
--mixed_precision was set to a value of 'no'
--dynamo_backend was set to a value of 'no'
To avoid this warning pass in values for each of the problematic parameters or run accelerate config.
/home/zhangkailin/.conda/envs/diff/lib/python3.12/site-packages/accelerate/utils/launch.py:236: UserWarning: Port 29500 is already in use. Accelerate will attempt to launch in a standalone-like mode by finding an open port automatically for this session. If this current attempt fails, or for more control in future runs, please specify a different port (e.g., --main_process_port <your_chosen_port>) or use --main_process_port 0 for automatic selection in your launch command or Accelerate config file.
warnings.warn(
[W718 20:29:59.662875029 socket.cpp:755] [c10d] The IPv6 network addresses of (I, 38455) cannot be retrieved (gai error: -2 - Name or service not known).
[W718 20:30:00.332290007 socket.cpp:755] [c10d] The IPv6 network addresses of (I, 38455) cannot be retrieved (gai error: -2 - Name or service not known).
[W718 20:30:01.086728483 socket.cpp:755] [c10d] The IPv6 network addresses of (I, 38455) cannot be retrieved (gai error: -2 - Name or service not known).
[W718 20:30:01.663832546 socket.cpp:755] [c10d] The IPv6 network addresses of (I, 38455) cannot be retrieved (gai error: -2 - Name or service not known).
[W718 20:30:02.003531155 socket.cpp:755] [c10d] The IPv6 network addresses of (I, 38455) cannot be retrieved (gai error: -2 - Name or service not known).
[W718 20:30:05.547585849 socket.cpp:755] [c10d] The IPv6 network addresses of (I, 38455) cannot be retrieved (gai error: -2 - Name or service not known).
[W718 20:30:10.156080575 socket.cpp:755] [c10d] The IPv6 network addresses of (I, 38455) cannot be retrieved (gai error: -2 - Name or service not known).
[W718 20:30:18.263436069 socket.cpp:755] [c10d] The IPv6 network addresses of (I, 38455) cannot be retrieved (gai error: -2 - Name or service not known).
[W718 20:30:28.254263791 socket.cpp:755] [c10d] The IPv6 network addresses of (I, 38455) cannot be retrieved (gai error: -2 - Name or service not known).

训练脚本

DIFFSYNTH_SKIP_DOWNLOAD=True \
CUDA_VISIBLE_DEVICES=0,1 \
NPROC_PER_NODE=2 \
accelerate launch examples/qwen_image/model_training/train.py \
  --dataset_base_path /appdata/zhangkailin/agent/wam/models_dd/guofeng \
  --dataset_metadata_path /appdata/zhangkailin/agent/wam/models_dd/guofeng/metadata.csv \
  --max_pixels 1572516 \
  --dataset_repeat 50 \
  --model_id_with_origin_paths "Qwen/Qwen-Image:transformer/diffusion_pytorch_model*.safetensors,Qwen/Qwen-Image:text_encoder/model*.safetensors,Qwen/Qwen-Image:vae/diffusion_pytorch_model.safetensors" \
  --learning_rate 1e-4 \
  --num_epochs 6 \
  --remove_prefix_in_ckpt "pipe.dit." \
  --save_steps 5 \
  --output_path "./models/train/Qwen-Image-2512_lora_0518" \
  --lora_base_model "dit" \
  --lora_target_modules "to_q,to_k,to_v,add_q_proj,add_k_proj,add_v_proj,to_out.0,to_add_out,img_mlp.net.2,img_mod.1,txt_mlp.net.2,txt_mod.1" \
  --lora_rank 16 \
  --find_unused_parameters \
  --dataset_num_workers 8 \
  --use_gradient_checkpointing \
  --gradient_accumulation_steps 4 \
  --find_unused_parameters \
  --wandb_project "qwen-image-guofeng" \
  --wandb_name "qwenimage-lora-codex200-0518"

Start with examples/qwen_image/model_training/train.py and the reported accelerate launch command, checking how the two-process launch selects its rendezvous address and port. Reproduce the command while examining the existing port-29500 warning and IPv6 name-resolution errors; done is a confirmed cause and a documented or implemented way to launch training without the reported failure.