Ok, thanks for the confirmation.
I started using Docker quite recently and I found interesting the way it can create and manage separated environments, and it is also a good tool to share an app with all its environment. So I searched for Docker image of pytorch, and I found the nvidia deep learning frameworks (free of access, only need to register your email). This catalog seems quite useful, all the release are described here. The only sad thing is it seems all the images described there seems to be build with pre-release versions of pytorch (like for example the pytorch V1.7 image you can found are based on: 1.7.0a0+7036e91 or 1.7.0a0+8deb4fe or 1.7.0a0+6392713). They did the same with the pre-release of v1.8 (1.8.0a0+17f8c32).
Maybe the simplest solution would be to switch to anaconda?
Anyways, thanks @ptrblck and @Nikronic for your answers. I will put this thread to solved has you pointed to the root cause of the problem, but don’t hesitate to let a message if you have any further remarks.