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Build CARLA ue5-dev from Source with ROS2 Support

This guide covers building CARLA UE5 (ue5-dev branch) from source on Linux using the manual/extended build path, with native ROS2 support enabled.

warning

The Unreal Engine 5 version of CARLA requires Ubuntu 22.04 at minimum. It has not been configured to build on older Ubuntu versions.

note

The official docs also offer a one-shot CarlaSetup.sh script that installs prerequisites, builds Unreal Engine, and builds CARLA all in one pass, with ROS2 enabled by default. This guide instead follows the manual/extended path, which gives more control and is what's needed if the setup script fails or you want to build Unreal Engine or content separately.

Prerequisite: Install Build Tools​

sudo apt update
sudo apt install build-essential ninja-build libvulkan1 python3 python3-dev python3-pip git git-lfs

Part 1. Build Unreal Engine​

CARLA UE5 uses a modified fork of Unreal Engine 5.5 maintained by CARLA.

note

Downloading this Unreal Engine fork requires a GitHub account that's linked to Epic Games' organization. If your account isn't linked yet, set that up first by following Epic's guide — otherwise the clone below will fail.

1.1 Clone the Unreal Engine Fork​

git clone --depth 1 -b ue5-dev-carla git@github.com:CarlaUnreal/UnrealEngine.git
cd UnrealEngine

1.2 Set Up and Build Unreal Engine​

./Setup.sh && ./GenerateProjectFiles.sh && make
note

The first build of Unreal Engine can take up to 3 hours.

1.3 Verify the Editor Opens​

Confirm Unreal Engine installed correctly by launching the editor:

cd Engine/Binaries/Linux
./UnrealEditor

If the editor opens without errors, the Unreal Engine build is complete.

1.4 Set the CARLA_UNREAL_ENGINE_PATH Environment Variable​

CARLA needs to know where your Unreal Engine build lives, so this environment variable has to be set.

To set it for just the current shell session:

export CARLA_UNREAL_ENGINE_PATH=<PATH_TO_UNREAL_ENGINE_FOLDER>

(Optional) To make it persist across sessions — useful if you plan to reconfigure or rebuild CARLA later in a fresh shell — add the same line to .bashrc or .profile:

echo 'export CARLA_UNREAL_ENGINE_PATH=<PATH_TO_UNREAL_ENGINE_FOLDER>' >> ~/.bashrc
source ~/.bashrc
warning

If CARLA_UNREAL_ENGINE_PATH isn't set, the CARLA build step later will instead download and build Unreal Engine itself, adding over an hour of build time and roughly 225 GB of disk space.

Part 2. Build CARLA​

2.1 Clone the CARLA Repository​

Clone the ue5-dev branch of the CARLA repository:

git clone https://github.com/carla-simulator/carla.git
note

ue5-dev is the repository's default branch, so no -b flag is needed here.

2.2 Clone the CARLA Content​

Clone the content repository into Unreal/CarlaUnreal/Content (create the folder first if it doesn't exist):

mkdir -p CARLA_ROOT/carla/Unreal/CarlaUnreal/Content
cd CARLA_ROOT/carla/Unreal/CarlaUnreal/Content
git clone --single-branch --depth 1 -b ue5-dev https://bitbucket.org/carla-simulator/carla-content.git Carla
note

This can take a while — it's downloading a large amount of asset data.

2.3 Configure CARLA with ROS2 Enabled​

From the root of the CARLA repo, set up a build preset with ROS2 support enabled:

cmake --preset Release -DENABLE_ROS2=ON
Preset names

The CARLA docs sometimes reference preset names like Linux-Release — these don't exist in CMakePresets.json. The actual preset names defined there are Debug, Development, and Release.

ROS2 is not enabled by any preset

None of the presets in CMakePresets.json set ENABLE_ROS2 — it defaults to off, which is why the flag above must be passed explicitly on the command line to get native ROS2 support. CMake merges it with the preset's existing cache variables.

note

If ROS2 dependencies (Fast-DDS, Fast-CDR, etc.) aren't discoverable at configure time, ENABLE_ROS2=ON may silently fail to pick them up. Check the configure log for ROS2-related messages after reconfiguring.

2.4 Build and Install the Python API​

cmake --build Build/Release --target carla-python-api-install

2.5 Launch the Editor​

cmake --build Build/Release --target launch

2.6 Build a Package​

cmake --build Build/Release --target package

The package is generated in $CARLA_PATH/Build/Package. Use the package-development target instead for a package with debug logging.

2.7 Run the Package​

The built package is located under Build/<preset>/Package/, in a folder named after the CARLA version and build type — for this build:

$CARLA_PATH/Build/Release/Package/Carla-0.10.0-Linux-Shipping/

From inside that package folder, run the simulator from the Linux subfolder:

cd Linux
./CarlaUnreal.sh --ros2

To use the Python API, you need to install the wheel that matches this package build — it's located under PythonAPI/carla/dist/ inside that same package folder:

sudo pip3 install PythonAPI/carla/dist/carla-***.whl --break-system-packages

Verify ROS2 Integration​

With the simulator running, list the available ROS2 topics:

ros2 topic list

A /clock topic confirms CARLA is publishing over ROS2 correctly:

/clock
/parameter_events
/rosout

If /clock is missing, native ROS2 support was not compiled in — go back to Part 2.3 and confirm ENABLE_ROS2=ON was passed during configure, then rebuild and repackage.