How to inference from RWKV checkpoint file

[chrischenhub]

Hi, I used the code to train a 169M rwkv model. But with the sample.py it seems like it can only do inference for GPT2 checkpoint, what should i modify the code to inference in rwkv checkpoint in a cpu only enviroment. Here is the error that I got from a no CUDA environment, does this mean that I must have a CUDA card to run inference?:
Traceback (most recent call last):
File "/Users/chris/Downloads/rwkv/sample.py", line 41, in
model = RWKV(gptconf)
File "/Users/chris/Downloads/rwkv/modeling_rwkv.py", line 277, in init
self.load_cuda_kernel(config.dtype)
File "/Users/chris/Downloads/rwkv/modeling_rwkv.py", line 602, in load_cuda_kernel
wkv_cuda = load(name=f"wkv_{T_MAX}_bf16", sources=["wkv_op_bf16.cpp", "wkv_cuda_bf16.cu"], verbose=True, extra_cuda_cflags=["-t 4", "-std=c++17", "-res-usage", "--maxrregcount 60", "--use_fast_math", "-O3", "-Xptxas -O3", "--extra-device-vectorization", f"-DTmax={T_MAX}"])
File "/Users/chris/opt/anaconda3/lib/python3.9/site-packages/torch/utils/cpp_extension.py", line 1308, in load
return _jit_compile(
File "/Users/chris/opt/anaconda3/lib/python3.9/site-packages/torch/utils/cpp_extension.py", line 1710, in _jit_compile
_write_ninja_file_and_build_library(
File "/Users/chris/opt/anaconda3/lib/python3.9/site-packages/torch/utils/cpp_extension.py", line 1800, in _write_ninja_file_and_build_library
extra_ldflags = _prepare_ldflags(
File "/Users/chris/opt/anaconda3/lib/python3.9/site-packages/torch/utils/cpp_extension.py", line 1899, in _prepare_ldflags
if (not os.path.exists(_join_cuda_home(extra_lib_dir)) and
File "/Users/chris/opt/anaconda3/lib/python3.9/site-packages/torch/utils/cpp_extension.py", line 2416, in _join_cuda_home
raise OSError('CUDA_HOME environment variable is not set. '
OSError: CUDA_HOME environment variable is not set. Please set it to your CUDA install root.