Steps needed to install K2 from scratch

install_k2.sh

#!/usr/bin/env bash

# Common steps
conda create -n k2 python=3.8
conda activate k2 
conda install -c nvidia cudnn=7.6.5 cudatoolkit=10.2
conda install -c pytorch pytorch torchaudio
pip install cmake
mkdir build
pushd build 

CONDA_ROOT="$(conda config --show root_prefix | cut -f2 -d' ')"
CONDA_ENV_DIR="$CONDA_ROOT/envs/k2"

# Note: somebody reported that they needed to pass an extra argument here:
# -DCUDA_TOOLKIT_ROOT_DIR=$CUDA_ROOT (where CUDA_ROOT points to the CUDA 
# installation used by PyTorch)
cmake \
  -DCMAKE_BUILD_TYPE=Release \
  -DCMAKE_CUDA_COMPILER=$(which nvcc) \
  -DPYTHON_EXECUTABLE=$(which python) \
  -DCUDNN_LIBRARY_PATH=$CONDA_ENV_DIR/lib/libcudnn.so \
  -DCUDNN_INCLUDE_PATH=$CONDA_ENV_DIR/include/ \
  ..
  
make -j24 _k2

popd

# When updating and rebuilding K2, before executing these steps, run:
# rm -rf dist/
scripts/build_pip.sh
pip install dist/*