Missing symbols from torch._C

Helo, I am running from pytorch master branch (building from source) and trying to do the following:

import torch._C._te as te

(this is from the functorch library)

I see that this should be available pytorch/tensorexpr_init.cpp at 59b28063b414c6184357d58987f66c469a2bbf7e · pytorch/pytorch · GitHub
Any pointers to why it might be missing? The import itself

import torch._C._te as te

works okay.

Sorry I found that was added even more recently than my master branch.

Our of curiosity incase anyone reading know: What is the op authoring project described in the MR?