mmcv installation

This always causes problems...

1) fail to build mmcv from the source, which was recommended by the egohumans repo

2) Why don't I just use pip and mim to install mmcv, mmdet as usual. 

3) The usual mmcv installation failed to import nms 

from mmcv.ops import nms

4) Ok, I found out that there is something called mmcv-full and I needed that for nms import (and potentially other functions that egohumans use)

5) Failed to install mmcv-full due to some gcc error. It was a version mismatch issue between Pytorch and mmcv-full. 

6) Downgraded pytorch 2.5 to 2.4, reinstalled the latest compatible mmcv that has mmcv-full in it according to this:

https://mmcv.readthedocs.io/en/latest/get_started/installation.html#install-mmcv-full

pip install mmcv==2.2.0 -f https://download.openmmlab.com/mmcv/dist/cu121/torch2.4/index.html

7) Still cannot import nms. Wtf. --no-cache --force-reinstall didn't work. Pip was keeping the old version mmcv 1.7 no matter what I do. Just did rm -rf .../site-packages/mmcv* and reinstalled. 

8) It worked. 

9) If you have to use some old versions of pytorch and mmcv, make sure to remove all mmcv packages and reinstall https://github.com/open-mmlab/mmdetection/issues/3271#issuecomment-1683581904

ModuleNotFoundError: No module named 'mmcv._ext' · Issue #3271 · open-mmlab/mmdetection

그러고 또 문제가있음. 진짜 얘네 어이가 없네. 뭔 api 관리를 이따위로 하냐. 그냥 torch version 낮추고 처음부터 다시 깔음.