Problem: nvcc not found, already installed cuda and driver
# local conda env fix
conda install -c nvidia cuda-toolkit=12.8
conda install -c nvidia cuda=12.8 (optional if cuda already installed)
which nvcc
nvcc --version
pip install flash-attn --no-build-isolation
export CUDA_HOME=$CONDA_PREFIX
export PATH=$CUDA_HOME/bin:$PATH
export LD_LIBRARY_PATH=$CUDA_HOME/lib64:$LD_LIBRARY_PATH
# system-wise fix
sudo apt-get update
sudo apt-get install -y nvidia-cuda-toolkit=12.8
which nvcc
nvcc --version
echo 'export PATH=/usr/local/cuda/bin:$PATH' >> ~/.bashrc
echo 'export CUDA_HOME=/usr/local/cuda' >> ~/.bashrc
source ~/.bashrc
# after nvcc is installed, then we can install flash attention
pip install flash-attn --no-build-isolation
