submodules install error

[2gouziqi]

Hi,

I met a problem regarding pip install submodules. I could pip install simple-knn but when I tried to pip install diff-gaussian-rasterization, I always met a problem saying:

ERROR: Could not find a version that satisfies the requirement diff-gaussian-rasterization (from versions: none)
ERROR: No matching distribution found for diff-gaussian-rasterization

Moreover, when I tried to cmake fast_gicp, another error happened:

CMake Error: The source directory "GS_ICP_SLAM-main/submodules/fast_gicp" does not appear to contain CMakeLists.txt.
Specify --help for usage, or press the help button on the CMake GUI.

Can you tell me how to do this?

Thank you so so much!