No GPU device detected despite by defalut log says use-device:gpu

[kshitizfrompali]

When i run a spacy pipeline without specifying spacy.require_gpu(), in log, it says: use-device:gpu but when i specify spacy.require_gpu(), it raises an error "No GPU devices detected."

spacy version:3.5.0
python version: 3.8.19

[kshitizfrompali]

The issue seems to get resolved after I installed:
pip install cupy-cuda11x
but why does it happen? Can anybody explain.

It detects when we don't define :
spacy.require_gpu

but when we define it didn't detect until I installed cupy-cuda11x.

It would be nice if someone explained in detail.
Thanks in advance.