mkdir -p ${PIP_CACHE_DIR}
# Let PIP do the work of downloading and verifying packages
-pip install --download ${PIP_CACHE_DIR} -r ${LIST}/pip-requirements.txt
+pip download -d ${PIP_CACHE_DIR} -r ${LIST}/pip-requirements.txt
# Link packages and requirements file into VM's temp directory
mkdir -p ${OUTPUT_DIR}/temp/pip