11 lines (9 with data), 269 Bytes

#!/bin/bash

export TMPDIR=$HOME/tmp
mkdir -p $TMPDIR
rm -rf apex
git clone https://github.com/NVIDIA/apex
cd apex
pip install -v --no-cache-dir --global-option="--cpp_ext" --global-option="--cuda_ext" ./ || pip install -v --no-cache-dir ./
cd ..
rm -rf apex