Setting up the waf Build Environment on Windows using Cygwin

These setup instructions describe how to setup Cygwin on so that waf (the build system) can run natively on windows and build for all supported boards.


There is a pre-built script at /ardupilot/Tools/environment_install/install-prereqs-windows.ps1 that will automatically perform all of the below steps.

Install Cygwin

  1. Open a web browser to and download “setup-x86_64.exe”
  2. Paste the following command at a DOS prompt (press window and R key then enter cmd) in the directory where you downloaded “Run setup-x86_64.exe”
setup-x86_64.exe -P autoconf,automake,ccache,cygwin32-gcc-g++,gcc-g++,git,libtool,make,gawk,libexpat-devel,libxml2-devel,python37,python37-future,python37-lxml,python37-pip,libxslt-devel,python37-devel,procps-ng,zip,gdb,ddd

Or, for a stepped install:

  1. Open a web browser to and run setup-x86_64.exe”

  2. Accept the prompts (including default file locations) until you reach the Select Packages dialog.

  3. Select the required packages from the thousands of available packages. Refer to the list below and enter each package “Name” into the Search field as shown below. When you have found the package, click on the Skip button to change it to a version number and then move onto the next package:


    Cygwin Installer: Select Package Dialog

    Package Name Category / Name / Description
    autoconf Devel | autoconf: Wrapper scripts for autoconf commands
    automake Devel | automake: Wrapper scripts for automake and aclocal
    ccache Devel | ccache: A C compiler cache for improving recompilation
    cygwin32-gcc-g++ Devel | GCC for Cygwin 32bit toolchain (C++)
    gcc-g++ Devel | gcc-g++ GNU Compiler Collection (C++)
    git Devel | git: Distributed version control system
    libtool Devel | libtool: Generic library support script
    make Devel | make: The GNU version of the ‘make’ utility
    gawk Interpreters | gawk: GNU awk, a pattern scanning and processing language
    libexpat-devel Libs | libexpat-devel: Expat XML parser library (development files)
    libxml2-devel Libs | libxml2-devel: Gnome XML library (development)
    libxslt-devel Libs | libxslt-devel: XML template library (development files)
    python37 Python | python37: Python3 language interpreter
    python37-devel Python | python37-devel: Python3 language interpreter
    python37-future Python | python37-future: Clean single-source support for Python 3 and 2
    python37-lxml Python | python37-lxml: Gnome XML Library (Python bindings)
    python37-pip Python | python37-pip: Python package installation tool
    procps-ng System | procps-ng: System and process monitoring utilities (required for pkill)
    gdb Devel | gdb: The GNU Debugger
    ddd Devel | ddd: DDD, the data display debugger
    zip Archive | zip: Info-ZIP compression utility
  4. When all the packages are selected, click through the rest of the prompts and accept all other default options (including the additional dependencies).

  5. Select Finish to start downloading and installing the packages.


    Sometimes the installation can stall because anti-virus protection software is running. If this occurs, shutdown all other programs on your PC including the anti-virus protection, and try again.

Install the GCC compiler


This step is only required if you intend to compile for ARM-based boards.

  1. Download and install the latest gcc-arm-non-eabi compiler from (quick link is here)
  2. Accept the license
  3. Install to the default location
  4. Accept the SSL certificate
  5. Check the option to “Add path to environment variable”

Install MAVProxy

The MAVProxy GCS is required when running SITL. If you’re not planning to run SITL, you can skip this step.

  1. To install MAVProxy on Windows follow the MAVProxy documentation.

Set up directories/paths and extra packages in Cygwin

  1. open and then close the “Cygwin Terminal” application from the desktop or start menu icon. This creates initialization files for the user in the Cygwin home directory.
  2. open the “Cygwin Terminal” application from the desktop or start menu icon. Enter the following command to set Python 3.7 to be the default Python and then install additional Python packages:
ln -s /usr/bin/python3.7 /usr/bin/python
ln -s /usr/bin/pip3.7 /usr/bin/pip
pip install empy pyserial pymavlink

Download ArduPilot Source

The ArduPilot source files then need to be downloaded to your local Cygwin filesystem by cloning the git repository and updating the submodules. Enter the following commands into the Cygwin terminal to download the source files:

git clone
cd ardupilot
git submodule update --init --recursive

Build with Waf

You should now be able to start the “Cygwin Terminal” application from your Windows Start menu and build with waf as described in


The build may fail if the file path to some files is too long. If the build fails, please try cloning ArduPilot into a directory very high in the directory structure (i.e. ~/ardupilot).

If during the build process you get an error of missing packet xyz, re-check that you have installed all Cygwin packages listed above

Running SITL

You can run SITL just as you can with any other build environment. To see the terminal, you should install VcXsrv or another X server application for Windows. You must then tell Cygwin where to look for the display by setting the DISPLAY variable.

export DISPLAY=:0.0

Build SITL binaries for Windows

You can build 32-bit binaries to be run outside of Cygwin with a small set of companion files. This can be useful when used in conjunction with Mission Planner to run SITL with a stable release build rather than a build from the development branch of ArduPilot. This can be done by compiling using the command below in Cygwin and copying the binary the “sitl” folder typically found at C:\Users\user\Documents\Mission Planner\sitl. Mission Planner will download the required files during the first time running SITL. After the initial run, the vehicle-specific binary file can be replaced with the file you built. The custom SITL binaries should be located at /ardupilot/build/sitl.

./waf configure --board=sitl --toolchain i686-pc-cygwin