I am currently getting the same issue with ATen/core/TensorBody.h not being found while trying to do a normal source compile of PyTorch 1.10.0 (for Linux, not a mobile build). PyTorch 1.9.1 and below build fine for me with the same setup.
I notice the file trying to be compiled when the error happens has ‘mobile’ in the path, so surely there is an issue that needs to be resolved?
I have been very careful with git and submodules etc, that is definitely not the problem.