Holoscan SDK — Build from Source

Purpose

Build the Holoscan SDK from the nvidia-holoscan/holoscan-sdk source tree using its ./run script (which builds inside a Docker container), producing a local install tree consumable as a CMake dependency.

Prerequisites

• Linux host with NVIDIA GPU + driver (nvidia-smi).
• git, Docker with NVIDIA Container Toolkit (docker run --gpus all works), and docker-buildx-plugin.
• ~20 GB free disk for the build container + build/install trees.
• 10–30 min for a clean first build.

Limitations

• Only recommended when published packages (Conda / container / apt / wheel) don't fit — debug symbols, custom CMake options, or unsupported configs.
• Still requires Docker — the ./run script builds inside a container; this is not a true bare-metal build.
• Cross-compiling to aarch64 needs qemu-user-static on the host.

Step 0: Consult the Official Install Instructions

Always fetch the "Build from Source" section of https://docs.nvidia.com/holoscan/sdk-user-guide/sdk_installation.html (and the linked GitHub README.md / DEVELOP.md for the chosen tag) before building. Extract: required ./run flags for the target architecture and CUDA major, supported branches/tags, any Dockerfile patches called out for the release, and the test names recommended for verification. If the doc disagrees with anything below, the doc wins.

Step 1: Prerequisites

Check that git and Docker (with GPU passthrough) are available:

git --version
docker --version
docker run --rm --gpus all ubuntu:22.04 nvidia-smi

• If Docker is missing → help install from https://docs.docker.com/engine/install/
• If GPU passthrough fails → install NVIDIA Container Toolkit:

  curl -fsSL https://nvidia.github.io/libnvidia-container/gpgkey | sudo gpg --dearmor -o /usr/share/keyrings/nvidia-container-toolkit-keyring.gpg
  curl -s -L https://nvidia.github.io/libnvidia-container/stable/deb/nvidia-container-toolkit.list \
    | sed 's#deb https://#deb [signed-by=/usr/share/keyrings/nvidia-container-toolkit-keyring.gpg] https://#g' \
    | sudo tee /etc/apt/sources.list.d/nvidia-container-toolkit.list
  sudo apt-get update && sudo apt-get install -y nvidia-container-toolkit
  sudo nvidia-ctk runtime configure --runtime=docker && sudo systemctl restart docker
  

• If Docker buildx is missing: sudo apt-get install docker-buildx-plugin

Step 2: Clone the Repository

Clone repo to ~/holoscan/holoscan-sdk if needed

mkdir -p ~/holoscan/
git clone https://github.com/nvidia-holoscan/holoscan-sdk.git
cd ~/holoscan/holoscan-sdk

To build a specific release tag (recommended for stability):

git tag | grep -E '^v[0-9]' | sort -V | tail -5   # list recent tags
git checkout v<VERSION>                             # e.g. v4.1.0

Step 3: Build

The ./run build script handles container creation, CMake configuration, compilation, and install in one step. Warn the user this takes 10–30 minutes on first run (downloads base image + compiles).

./run build

Common options:

Flag	Purpose
--type debug	Debug build (symbols, no optimization)
--type RelWithDebInfo	Release + debug symbols
--arch aarch64	Cross-compile for ARM64 (needs sudo apt install qemu-user-static)
--gpu igpu	iGPU build for Jetson/IGX
--dryrun	Preview commands without executing

If CMake cache errors occur after changing options:

./run clear_cache && ./run build

Output lands in these folders, and can be retrieved with ./run get_build_dir and ./run get_install_dir

• Build dir: build-cu<N>-<arch>/
• Install dir: install-cu<N>-<arch>/.

Step 4: Run Tests

Run the following tests

• EXAMPLE_CPP_HELLO_WORLD_TEST
• EXAMPLE_PYTHON_HELLO_WORLD_TEST
• EXAMPLE_CPP_TENSOR_INTEROP_TEST
• EXAMPLE_PYTHON_TENSOR_INTEROP_TEST
• EXAMPLE_CPP_VIDEO_REPLAYER_TEST
• EXAMPLE_PYTHON_VIDEO_REPLAYER_TEST

./run test

To run all six required tests at once, use a single-quoted regex (the | must be quoted to prevent bash from treating it as a pipe):

./run test --options "-R 'EXAMPLE_CPP_HELLO_WORLD_TEST|EXAMPLE_PYTHON_HELLO_WORLD_TEST|EXAMPLE_CPP_TENSOR_INTEROP_TEST|EXAMPLE_PYTHON_TENSOR_INTEROP_TEST|EXAMPLE_CPP_VIDEO_REPLAYER_TEST|EXAMPLE_PYTHON_VIDEO_REPLAYER_TEST' --output-on-failure"

Run a specific test by name or regex:

./run test --name <test_name>
./run test --options "-R '<regex>' --output-on-failure"
./run test --verbose

Important: Always single-quote the regex string when it contains | — without quotes, bash interprets | as a pipe and the command fails with command not found.

Expected: all tests pass. Note any failures and report them to the user before continuing.

Step 5: Point Applications at the Install Tree

Once built, applications can use the install tree as a CMake dependency. Give the user this path:

/path/to/holoscan-sdk/install-cu<N>-<arch>/

They can set Holoscan_ROOT or CMAKE_PREFIX_PATH to this directory when building their own applications.

Troubleshooting

Symptom	Fix
bash: <TEST_NAME>: command not found when running tests	The regex contains | — wrap it in single quotes: --options "-R '<regex>'"
CMake cache errors after option change	./run clear_cache && ./run build
Docker buildx not found	sudo apt-get install docker-buildx-plugin
GPU not visible inside build container	Verify NVIDIA Container Toolkit and re-run sudo nvidia-ctk runtime configure --runtime=docker
Cross-compile fails (aarch64)	Install qemu: sudo apt-get install qemu-user-static