Unable to download Tensorflow C Language Bindings as an ExternalProject - cmake

Question

I'm trying to include the C language bindings for Tensorflow found at https://storage.googleapis.com/tensorflow/libtensorflow/libtensorflow-gpu-linux-x86_64-2.5.0.tar.gz in my CMake Project. Unfortunately, it seems as thought nothing is being downloaded, as the TENSORFLOW-prefix/src/TENSORFLOW directory is empty. I'm new to CMake and am not sure where I am going wrong. Any help would be appreciated.
Relevant source:
cmake_minimum_required(VERSION 3.17)
include(ExternalProject)
project(tfexec)
set(CMAKE_CXX_STANDARD 17)
ExternalProject_Add(TENSORFLOW
URL "https://storage.googleapis.com/tensorflow/libtensorflow/libtensorflow-gpu-linux-x86_64-2.5.0.tar.gz"
CONFIGURE_COMMAND ""
BUILD_COMMAND ""
INSTALL_COMMAND ""
LOG_DOWNLOAD 1
LOG_CONFIGURE 1
LOG_BUILD 1
LOG_INSTALL 1
)

Answer 1

ExternalProject runs at build time, so you actually need to run your build for this to do anything. This is what I see; it seems to be working fine:
alex#Alex-Desktop:~/test$ cmake-3.17 -S . -B build -DCMAKE_BUILD_TYPE=Release
...
-- Configuring done
-- Generating done
-- Build files have been written to: /home/alex/test/build
alex#Alex-Desktop:~/test$ cmake --build build/ -- -v
...
alex#Alex-Desktop:~/test$ tree build/TENSORFLOW-prefix/src/TENSORFLOW
build/TENSORFLOW-prefix/src/TENSORFLOW
├── LICENSE
├── THIRD_PARTY_TF_C_LICENSES
├── include
│   └── tensorflow
│   ├── c
│   │   ├── c_api.h
│   │   ├── c_api_experimental.h
│   │   ├── c_api_macros.h
│   │   ├── eager
│   │   │   ├── c_api.h
│   │   │   ├── c_api_experimental.h
│   │   │   └── dlpack.h
│   │   ├── tensor_interface.h
│   │   ├── tf_attrtype.h
│   │   ├── tf_datatype.h
│   │   ├── tf_file_statistics.h
│   │   ├── tf_status.h
│   │   ├── tf_tensor.h
│   │   └── tf_tstring.h
│   └── core
│   └── platform
│   ├── ctstring.h
│   └── ctstring_internal.h
└── lib
├── libtensorflow.so -> libtensorflow.so.2
├── libtensorflow.so.2 -> libtensorflow.so.2.5.0
├── libtensorflow.so.2.5.0
├── libtensorflow_framework.so -> libtensorflow_framework.so.2
├── libtensorflow_framework.so.2 -> libtensorflow_framework.so.2.5.0
└── libtensorflow_framework.so.2.5.0
7 directories, 23 files