Holoscan Conda Installation

Purpose

Install the Holoscan SDK (Python runtime and/or C++ dev headers) into a Conda environment on Linux x86_64, using conda-forge + rapidsai with a correctly pinned CUDA metapackage.

Prerequisites

Linux x86_64 with an NVIDIA GPU and CUDA 13 driver (check
```
nvidia-smi
```
).
```
conda
```
(Miniforge preferred). Step 1 installs it if missing.
Network access to conda-forge, rapidsai, and
```
docs.nvidia.com
```
.

Limitations

CUDA 13 only (since v4.3.0 — earlier releases were CUDA 12). If the user has a CUDA 12 driver, redirect to
```
/holoscan-install-container
```
or
```
/holoscan-install-wheel
```
instead.
Linux x86_64 only — no aarch64/iGPU support on conda-forge.
```
ulimit -s 32768
```
is recommended in every shell that runs Holoscan — without it, some apps may segfault.

Step 0: Consult the Official Install Instructions

Always fetch the current Conda section of

https://docs.nvidia.com/holoscan/sdk-user-guide/sdk_installation.html

before installing — package names, channel selection, and the runtime/dev split can change between releases. Specifically extract:

The exact runtime package name (e.g.
```
holoscan
```
for Python bindings).
The C++ dev package name and whether the user needs it. As of v4.1.0,
```
libholoscan-dev
```
is a separate package containing headers and CMake config — install it whenever the user wants to develop C++ apps. Without it,
```
find_package(holoscan)
```
fails and there are no headers to
```
#include
```
.
Supported Python versions for the current release (3.10–3.13 for v4.3).
The current
```
cuda-version
```
pin (v4.3 →
```
13
```
).

rmm

and

ucxx

are distributed via the

rapidsai

channel;

holoscan

libholoscan

, and

libholoscan-dev

come from

conda-forge

If the doc disagrees with anything below, the doc wins — update the install commands accordingly and tell the user.

Step 1: Prerequisites Check

bash

conda --version 2>&1
nvidia-smi 2>&1 | head -5

conda

is not found, install Miniforge silently (preferred over Miniconda for conda-forge):

bash

wget -q https://github.com/conda-forge/miniforge/releases/latest/download/Miniforge3-Linux-x86_64.sh -O /tmp/Miniforge3.sh
bash /tmp/Miniforge3.sh -b -p ~/miniforge3
source ~/miniforge3/etc/profile.d/conda.sh
conda --version

The

-b

flag installs non-interactively without modifying

.bashrc

. Users must

source ~/miniforge3/etc/profile.d/conda.sh

in each new shell (or add it to their shell RC file) to make

conda

available.

Step 2: Create Environment and Install

Package roles

```
libholoscan
```
— C++ runtime symbols (
```
libholoscan_core.so
```
). Auto-pulled as a dependency.
```
holoscan
```
— Python bindings.

libholoscan-dev

— C++ headers,

libholoscan_core.so

symlink, and

holoscan-config.cmake

for

find_package(holoscan)

```
rmm
```
— RAPIDS Memory Manager (rapidsai channel). Undeclared runtime dep of
```
holoscan
```
;
```
import holoscan
```
fails without it.
```
ucxx
```
— UCX Python bindings (rapidsai channel), needed for distributed/multi-process apps.
```
cuda-version=13
```
— pins the CUDA 13 metapackage so the solver picks compatible CUDA runtime libs.

Create the environment first:

bash

source ~/miniforge3/etc/profile.d/conda.sh   # if conda not yet on PATH
conda create -n holoscan python=3.13 -y
conda activate holoscan

Then pick one of the variants below based on the user's goal.

Pick the packages for the user's goal — Python-only needs

holoscan

, C++ dev needs

libholoscan-dev

, both works for combined use:

bash

conda install <packages> rmm ucxx cuda-version=13 -c rapidsai -c conda-forge -y

For C++ development, also install the toolchain:

bash

conda install -c conda-forge cxx-compiler cmake ninja -y

Verify Python installs with

python3 -c "import holoscan; print(holoscan.__version__)"

. Verify C++ dev installs with

ls "$CONDA_PREFIX/include/holoscan"

Step 3: Run Python Tests

ulimit -s 32768

is recommended — without it, some Holoscan apps may segfault on startup.

video_replayer

is a display app that loops forever by default. Always patch its YAML to stop after 10 frames (

count: 10

repeat: false

realtime: false

) and to run headless (

headless: true

) — headless works with or without a display attached and avoids GUI failure modes over SSH, so we don't branch on

$DISPLAY

Download scripts and YAML configs, patch the YAML, then run:

bash

source ~/miniforge3/etc/profile.d/conda.sh
conda activate holoscan
ulimit -s 32768

SDK_VER=$(python3 -c "import holoscan; print(holoscan.__version__)")
BASE="https://raw.githubusercontent.com/nvidia-holoscan/holoscan-sdk/v${SDK_VER}/examples"

curl -fsSL "${BASE}/hello_world/python/hello_world.py"         -o /tmp/hs_hello_world.py
curl -fsSL "${BASE}/video_replayer/python/video_replayer.py"   -o /tmp/hs_video_replayer.py
curl -fsSL "${BASE}/video_replayer/python/video_replayer.yaml" -o /tmp/video_replayer.yaml

# Patch video_replayer.yaml — 10 frames, headless.
python3 -c "
c = open('/tmp/video_replayer.yaml').read()
c = c.replace('count: 0', 'count: 10')
c = c.replace('repeat: true', 'repeat: false')
c = c.replace('realtime: true', 'realtime: false')
c = c.replace('  width: 854', '  headless: true\n  width: 854')
open('/tmp/video_replayer.yaml', 'w').write(c)"

# hello_world — no display, no data needed; expected: "Hello World!"
python3 /tmp/hs_hello_world.py

# video_replayer — needs racerx data; expected: frames rendered, "Graph execution finished."
HOLOSCAN_INPUT_PATH=/path/to/holoscan/data python3 /tmp/hs_video_replayer.py

HOLOSCAN_INPUT_PATH

must point to the directory containing a

racerx/

subdirectory. If the user has the SDK source repo that is

~/repos/holoscan-sdk/data

; otherwise download with the

download_ngc_data

script from the Debian or source install tree.

Step 4: Remind the User

They must do the following in each new shell session:

bash

source ~/miniforge3/etc/profile.d/conda.sh   # if Miniforge was installed with -b
conda activate holoscan
ulimit -s 32768   # recommended — prevents segfaults in some apps

Consider adding these lines to

~/.bashrc

~/.zshrc

to avoid repeating them.

Then offer next steps:

Explore C++ and Python examples at

https://github.com/nvidia-holoscan/holoscan-sdk/tree/v<VERSION>/examples

Walk through a specific example:
```
/explain-example
```
Start building a custom Holoscan application

Troubleshooting

ImportError: librmm.so: cannot open shared object file
.
```
rmm
```
was not installed. Re-run the Step 2
```
conda install
```
line —
```
rmm
```
is an undeclared runtime dependency of
```
holoscan
```
.
Solver picks an older
holoscan
build than expected. Channel order may be wrong. Use
```
-c rapidsai -c conda-forge
```
(rapidsai first) — that's the order in the official install command, and under strict channel priority a conda-forge-first ordering can lock the solver to an older
```
holoscan
```
build.
Segmentation fault on app startup. Set
```
ulimit -s 32768
```
in the current shell before running any Holoscan app. Not all apps trip this, but the larger stack avoids the failure mode.
find_package(holoscan)
fails when building C++ apps. Install
```
libholoscan-dev
```
(headers + CMake config are in a separate package since v4.1.0).
conda: command not found
in a new shell. Miniforge was installed with
```
-b
```
and did not patch
```
.bashrc
```
. Run
```
source ~/miniforge3/etc/profile.d/conda.sh
```
or add it to your shell RC file.

holoscan-install-conda

NPX Install

Tags

SKILL.md Content

Holoscan Conda Installation

Purpose

Prerequisites

Limitations

Step 0: Consult the Official Install Instructions

Step 1: Prerequisites Check

Step 2: Create Environment and Install

Package roles

Step 3: Run Python Tests

Step 4: Remind the User

Troubleshooting