TotalSegmentator install problem - pytorch version?

[mhopeng (Matthew Hopcroft)]

Hello, I’ve tried to install TotalSegmentator on two macOS systems. When I try to run the sample data set, I get an error that seems to be related to the PyTorch version:

ImportError: cannot import name ‘GradScaler’ from ‘torch’ (/Applications/Slicer.app/Contents/lib/Python/lib/python3.12/site-packages/torch/_init_.py)

A google search suggests that this is a problem with the PyTorch version. The PyTorch installation appears to be managed by a Slicer extension. Is there a version mismatch, or am I on the wrong track here?

[jamesobutler (James Butler)]

The following about downgrading the nnunetv2 version may help:

Version 5.10.0, error in total segmentator

This appears to be an issue introduced by NNunetv2 developers. This package is a dependency of TotalSegmentator. A possible workaround is to open the NNunet Slicer module which is used for installing versions of the package. Choose to install nnunetv2<2.6 as it seems like the nnunetv2 2.6.0 version introduced this error that requires torch 2.6.0 and later for the CPU version of GradScaler. Unfortunately, on macOS Slicer factory builds are still x86_64 builds with no native arm64 build. The lat…