AssertionError: Default process group is not initialized

[bushou-yhh]

[10/16 15:51:32 pods.engine.trainer]: Starting training from iteration 0
ERROR [10/16 15:51:32 pods.engine.trainer]: Exception during training:
Traceback (most recent call last):
File "/media/sda6/yhh/FCOS/BorderDet/cvpods/engine/trainer.py", line 89, in train
self.run_step()
File "/media/sda6/yhh/FCOS/BorderDet/cvpods/engine/trainer.py", line 193, in run_step
loss_dict = self.model(data)
File "/home/yons/anaconda3/envs/borderdet140-yhh/lib/python3.7/site-packages/torch/nn/modules/module.py", line 532, in call
result = self.forward(*input, **kwargs)
File "/media/sda6/yhh/FCOS/BorderDet/cvpods/modeling/meta_arch/borderdet.py", line 167, in forward
bd_box_delta,
File "/media/sda6/yhh/FCOS/BorderDet/cvpods/modeling/meta_arch/borderdet.py", line 237, in losses
dist.all_reduce(num_foreground)
File "/home/yons/anaconda3/envs/borderdet140-yhh/lib/python3.7/site-packages/torch/distributed/distributed_c10d.py", line 901, in all_reduce
_check_default_pg()
File "/home/yons/anaconda3/envs/borderdet140-yhh/lib/python3.7/site-packages/torch/distributed/distributed_c10d.py", line 193, in _check_default_pg
"Default process group is not initialized"
AssertionError: Default process group is not initialized
[10/16 15:51:32 pods.engine.hooks]: Total training time: 0:00:00 (0:00:00 on hooks)

[bushou-yhh]

soft link to Outputs/model_logs/cvpods_playground/detection/coco/borderdet/borderdet.res101.fpn.coco.800size.2x
Command Line Args: Namespace(dist_url='tcp://127.0.0.1:50152', eval_only=False, machine_rank=0, num_gpus=1, num_machines=1, opts=[], resume=False)
[10/16 16:29:02 cvpods]: Rank of current process: 0. World size: 1
[10/16 16:29:02 cvpods]: Environment info:

---

sys.platform linux
Python 3.7.9 (default, Aug 31 2020, 12:42:55) [GCC 7.3.0]
numpy 1.18.2
cvpods 0.1 @/media/sda6/yhh/FCOS/BorderDet/cvpods
cvpods compiler GCC 5.5
cvpods CUDA compiler 10.1
cvpods arch flags sm_61
cvpods_ENV_MODULE
PyTorch 1.4.0 @/home/yons/anaconda3/envs/borderdet140-yhh/lib/python3.7/site-packages/torch
PyTorch debug build False
CUDA available True
GPU 0 GeForce GTX 1080 Ti
CUDA_HOME /usr/local/cuda-10.1
NVCC Cuda compilation tools, release 10.1, V10.1.105
Pillow 6.2.0
torchvision 0.5.0 @/home/yons/anaconda3/envs/borderdet140-yhh/lib/python3.7/site-packages/torchvision
torchvision arch flags sm_35, sm_50, sm_60, sm_70, sm_75
cv2 4.4.0

---

PyTorch built with:

• GCC 7.3
• Intel(R) Math Kernel Library Version 2020.0.2 Product Build 20200624 for Intel(R) 64 architecture applications
• Intel(R) MKL-DNN v0.21.1 (Git Hash 7d2fd500bc78936d1d648ca713b901012f470dbc)
• OpenMP 201511 (a.k.a. OpenMP 4.5)
• NNPACK is enabled
• CUDA Runtime 10.1
• NVCC architecture flags: -gencode;arch=compute_37,code=sm_37;-gencode;arch=compute_50,code=sm_50;-gencode;arch=compute_60,code=sm_60;-gencode;arch=compute_61,code=sm_61;-gencode;arch=compute_70,code=sm_70;-gencode;arch=compute_75,code=sm_75;-gencode;arch=compute_37,code=compute_37
• CuDNN 7.6.3
• Magma 2.5.1
• Build settings: BLAS=MKL, BUILD_NAMEDTENSOR=OFF, BUILD_TYPE=Release, CXX_FLAGS= -Wno-deprecated -fvisibility-inlines-hidden -fopenmp -DUSE_FBGEMM -DUSE_QNNPACK -DUSE_PYTORCH_QNNPACK -O2 -fPIC -Wno-narrowing -Wall -Wextra -Wno-missing-field-initializers -Wno-type-limits -Wno-array-bounds -Wno-unknown-pragmas -Wno-sign-compare -Wno-unused-parameter -Wno-unused-variable -Wno-unused-function -Wno-unused-result -Wno-strict-overflow -Wno-strict-aliasing -Wno-error=deprecated-declarations -Wno-stringop-overflow -Wno-error=pedantic -Wno-error=redundant-decls -Wno-error=old-style-cast -fdiagnostics-color=always -faligned-new -Wno-unused-but-set-variable -Wno-maybe-uninitialized -fno-math-errno -fno-trapping-math -Wno-stringop-overflow, DISABLE_NUMA=1, PERF_WITH_AVX=1, PERF_WITH_AVX2=1, PERF_WITH_AVX512=1, USE_CUDA=ON, USE_EXCEPTION_PTR=1, USE_GFLAGS=OFF, USE_GLOG=OFF, USE_MKL=ON, USE_MKLDNN=ON, USE_MPI=OFF, USE_NCCL=ON, USE_NNPACK=ON, USE_OPENMP=ON, USE_STATIC_DISPATCH=OFF,

[10/16 16:29:02 cvpods]: Command line arguments: Namespace(dist_url='tcp://127.0.0.1:50152', eval_only=False, machine_rank=0, num_gpus=1, num_machines=1, opts=[], resume=False)

[bushou-yhh]

in cvpods/engine/launch.py
I changed
if world_size > 1:
# pytorch/pytorch#14391
# TODO prctl in spawned processes
to
if world_size >= 1:
# pytorch/pytorch#14391
# TODO prctl in spawned processes

it works

[FateScript]

Well, seems you are using 1-GPU during training? Such an error shouldn't happen. Could you please provide command your are using ?

[FateScript]

Since the reporter doesn't reply for a week, We close this issue.