CARLA 0.9.16 Windows Build Guide

Practical guide for building CARLA 0.9.16 from source on Windows, written from a build actually carried out at C:\src_ext\CarlaSrc_0_9_16 (tag 0.9.16).

The 0.9.15 guide is Carla_Windows_building.md, and the Linux counterpart is Carla_Linux_building.md. Read this one instead of the 0.9.15 guide if you are building 0.9.16 — the toolchain changed and most of the 0.9.15 workarounds no longer apply.

Official baseline: CARLA 0.9.16 Windows build docs.

Why we care about 0.9.16. It adds vehicle.get_telemetry_data(), which reports per-wheel tire force, wheel speed, slip and load, plus the vehicle’s aero drag. That is what the XIL dyno coupling needs — see xil/CarlaDynoCoupling.md. Migration status for FIXS is tracked in issue #319.

1. What changed from 0.9.15

	0.9.15	0.9.16
Visual Studio	2019 (`vc142`)	2022 (`vc143`) — hardcoded, see §2.1
Boost	1.80.0	1.84.0
Unreal Engine	CARLA fork of UE 4.26	same fork, no engine rebuild needed
Python wheel build	`setup.py bdist_wheel`	`python -m build`
Content assets	`20231108_c5101a5`	`20250912_2171890` (20.1 GB)

The single most useful thing to know: the UE 4.26 fork does not change. If you already have CarlaUnreal/UnrealEngine (the carla branch) built for 0.9.15, point UE4_ROOT at it and reuse it as-is.

2. Prerequisites

Same as 0.9.15 except the compiler:

Visual Studio 2022 with the C++ toolset and Windows 10/11 SDK. 0.9.15 needed VS2019; 0.9.16 does not build with it (§2.1).
Make 3.81 exactly — CARLA pins this version. Install via GnuWin32.
CMake 3.15+ (3.31.9 verified).
7-Zip, on PATH or installed to %ProgramW6432%\7-Zip.
Python 3.10 with py and py3 resolving to it. The py.ini procedure in the 0.9.15 guide §Part Two.6 still applies verbatim.
UE 4.26 CARLA fork at %UE4_ROOT%.

Python packages, under Python 3.10 specifically:

py -3.10 -m pip install build distro wheel setuptools "numpy<2.0.0"

build is new for 0.9.16 (§3.3) and numpy<2.0.0 is still required.

2.1 The VS2022 requirement is hardcoded

0.9.15 passed the boost toolset through a variable; 0.9.16 pins it:

0.9.15   Setup.bat  --boost-toolset $(TOOLSET)     configurable
0.9.16   Setup.bat  --boost-toolset msvc-14.3      hardcoded  (vc143 = VS2022)

So build with VS2022 and pass the matching generator (§3.1).

3. Build procedure

Run everything from a VS2022 x64 Native Tools environment. The CARLA Makefile does not source vcvars64.bat itself.

Two Windows-specific traps before you start:

Do not drive the build from Git Bash. Its POSIX PATH leaks into cmd and breaks vcvars64.bat with Unknown parameter: path. Use cmd or PowerShell.
If launching from PowerShell, PowerShell sets NoDefaultCurrentDirectoryInExePath=1, which cmd inherits and which makes call bootstrap.bat fail even though the file is right there. Clear it first:
```
set "NoDefaultCurrentDirectoryInExePath="
```

3.1 Dependencies

call "C:\Program Files\Microsoft Visual Studio\2022\Community\VC\Auxiliary\Build\vcvars64.bat"
set "UE4_ROOT=C:\src_ext\CarlaUnreal"
cd /d C:\src_ext\CarlaSrc_0_9_16
make setup GENERATOR="Visual Studio 17 2022"

make setup and make PythonAPI can exit 0 while having failed. The batch wrappers swallow the real exit code. Always verify the artifacts exist rather than trusting the return code.

3.2 Patch: trailing-backslash quote escape (7 sites)

Symptom

'bootstrap.bat' is not recognized as an internal or external command

Cause The build directory is passed as "C:\...\Build\". In batch, \" escapes the quote rather than closing it, so cd "%VAR%" silently fails and the script then cannot find the file it is about to run.

Fix Append a dot so the quote closes properly, in all 7 places:

cd "%BOOST_SRC_DIR%"      ->   cd "%BOOST_SRC_DIR%."

Files under Util/InstallersWin/: install_boost.bat, install_chrono.bat, install_fastDDS.bat, install_gtest.bat, install_recast.bat (twice), install_rpclib.bat.

The 0.9.15 guide describes this same fix but gives the directory as Util/InstallerWin. The correct path is Util/InstallersWin (with the s).

3.3 Patch: boost bootstrap toolset

Util/InstallersWin/install_boost.bat calls bootstrap.bat vc141 (VS2017), which is not installed. Change to match the toolset the same file already defaults to:

call bootstrap.bat vc143

3.4 Patch: `python -m build` isolation

Symptom make PythonAPI exits 4294967295.

Cause 0.9.16 builds the wheel with python -m build, which creates an isolated venv whose bundled pip (23.0.1) fails against modern setuptools.

Fix Util/BuildTools/BuildPythonAPI.bat line 99 — build in the current environment:

python -m build --wheel --no-isolation --outdir dist\.tmp .

3.5 Patch: MSVC internal compiler error and COFF section limit

Symptom 1

boost/math/special_functions/trigamma.hpp(147): fatal error C1001: Internal compiler error.

MSVC 14.43 ICEs on boost 1.84’s math headers under setuptools’ default /O2 /GL.

Symptom 2, once that is past:

class.hpp(590): fatal error C1128: number of sections exceeded object file format limit

Fix Both in PythonAPI/carla/setup.py. setuptools injects its flags first and CARLA appends after, so a later /GL- wins:

'/DLIBCARLA_WITH_PYTHON_SUPPORT', '-DLIBCARLA_IMAGE_WITH_PNG_SUPPORT=true', '/MD',
# MSVC 14.43 ICEs (C1001) on boost 1.84 math headers under /GL.
'/GL-',
# boost.python generates more sections than the COFF limit allows
'/bigobj']

3.6 Build the Python client

make PythonAPI

Verify — do not trust the exit code:

PythonAPI\carla\dist\carla-0.9.16-cp310-cp310-win_amd64.whl

Install it and confirm the telemetry API is present:

py -3.10 -m pip install PythonAPI\carla\dist\carla-0.9.16-cp310-cp310-win_amd64.whl
py -3.10 -c "import carla; print(carla.Vehicle.get_telemetry_data, carla.WheelTelemetryData.omega)"

3.7 Content assets

Util/ContentVersions.txt maps versions to asset packages. For 0.9.16 it is 20250912_2171890. If Update.bat fails (it often does), download directly — 20.1 GB:

https://carla-assets.s3.us-east-005.backblazeb2.com/20250912_2171890.tar.gz

Extract into Unreal/CarlaUE4/Content/Carla/. The archive has no top-level directory prefix, so it expands straight into that folder — do not create a nested one.

4. Running the server

4.1 `make package` does not work

ScriptCompiler.CompileAutomationProjects
  -> MSBuild.exe  ExitCode=-1073741819      (0xC0000005, access violation)

UE 4.26’s AutomationTool crashes under the VS2022 toolchain that 0.9.16 requires (§2.1). This is unresolved. It blocks producing a distributable package; it does not block using CARLA from source.

4.2 Launch from source instead

make CarlaUE4Editor

This succeeds (751/751 modules). It produces CarlaUE4.exe, but that is the game target and will refuse to start:

Your application is built to load COOKED content. No COOKED content was found

Cooking is what make package would have done. Launch the way CARLA itself does (Util/BuildTools/BuildCarlaUE4.bat:205) — through the engine’s editor binary, which loads uncooked content directly:

"%UE4_ROOT%\Engine\Binaries\Win64\UE4Editor.exe" ^
    C:\src_ext\CarlaSrc_0_9_16\Unreal\CarlaUE4\CarlaUE4.uproject ^
    -game -carla-server -carla-rpc-port=2000 -RenderOffScreen -quality-level=Low -nosound

Drop -RenderOffScreen if you want a window.

4.3 Confirm it works

import carla
c = carla.Client("127.0.0.1", 2000); c.set_timeout(10.0)
print(c.get_server_version(), c.get_client_version())   # both: 294096e-dirty

Verified on this build: Town10HD_Opt, 25 NPC vehicles spawned with 24 driving under Traffic Manager, four synchronous-mode client sessions totalling ~5000 ticks, no errors in the server log.

Probe scripts that exercise the server and the telemetry API live on the investigation branch under doc/xil/carla0916_probes/ — see issue #319.

5. Known-good configuration


CARLA	tag `0.9.16`, reports `294096e-dirty`
Unreal Engine	CARLA fork of 4.26 at `C:\src_ext\CarlaUnreal` (shared with 0.9.15)
Visual Studio	2022 Community, MSVC 14.43.34808
CMake / Make	3.31.9 / 3.81
Python	3.10.11
Boost	1.84.0 (`vc143`)
Assets	`20250912_2171890`
Source tree	`C:\src_ext\CarlaSrc_0_9_16`

6. Upstream defects

Four of the patches above are CARLA bugs, not environment quirks, and are worth reporting upstream:

§3.2 trailing-backslash quote escape in Util/InstallersWin/*.bat
§3.3 bootstrap.bat vc141 against a msvc-14.3 default
§3.5 no /GL- guard for the boost 1.84 ICE
§3.5 no /bigobj for boost.python