ImportError: cannot import name 'deform_conv_cuda' from partially initialized module 'assets.ops.dcn'

解决：

cd assets/ops/dcn/

python setup.py build_ext --inplace

新问题：

from src/deform_conv_cuda.cpp:4:
/usr/include/c++/5/cstddef:45:20: fatal error: stddef.h: 没有那个文件或目录
compilation terminated.
error: command 'gcc' failed with exit status 1
(base) admin××××××/assets/ops/dcn$ find /usr -name stddef.h
find: `/usr/lib/python3/dist-packages/po': 权限不够
find: `/usr/lib/python3/dist-packages/tools': 权限不够
/usr/lib/gcc/x86_64-linux-gnu/4.9/include/stddef.h
/usr/include/linux/stddef.h
/usr/src/linux-headers-4.4.0-21/include/linux/stddef.h
/usr/src/linux-headers-4.4.0-21/include/uapi/linux/stddef.h
/usr/src/linux-headers-4.4.0-186/include/linux/stddef.h
/usr/src/linux-headers-4.4.0-186/include/uapi/linux/stddef.h
/usr/src/linux-headers-4.4.0-187/include/linux/stddef.h
/usr/src/linux-headers-4.4.0-187/include/uapi/linux/stddef.h
/usr/src/linux-headers-4.4.0-189/include/linux/stddef.h
/usr/src/linux-headers-4.4.0-189/include/uapi/linux/stddef.h