🐛 Bug

torch_xla.runtime.global_runtime_device_count() always return one and the value of GPU_NUM_DEVICES is set to four.

To Reproduce

run PJRT_DEVICE=CUDA GPU_NUM_DEVICES=4 python test.py

the content of test.py as follows

import torch_xla
from torch_xla import runtime as xr
print('global_runtime_device_count: ', xr.global_runtime_device_count())

output is

global_runtime_device_count:  1

Expected behavior

I want the value of xr.global_runtime_device_count() to be equal to the value of GPU_NUM_DEVICES.
or
There is a mistake in my understanding of xr.global_runtime_device_count()

Environment

• Reproducible on XLA backend [CPU/TPU]: CUDA
• torch_xla version: 2.2.0+git4038f8e

Additional context

None