Preparing Windows

Building on windows is significantly more complex than building on macos or linux. This guide will walk you through preparing your Windows machine for building a Firefox fork. Before building, you should be aware that only Windows 10 or 11 are officially supported, but you might be able to get other versions to work.

Installing Dependencies

The first thing you will need to do is install Microsoft's c++ build tools. You will need to download Build Tools for Visual Studio 2022. The following will need to be installed:

• In the Workloads tab

  • Desktop development with C++

• In the Individual components tab

  • MSVC v143 - VS 2022 C++ x64/x86 build tools.

  • Windows 10 SDK (at least 10.0.19041.0).

  • C++ ATL for v143 build tools (x86 and x64).

Note: If this guide ever gets out of date, you can get the latest build requirements from Mozilla's docs

You will need to install MozillaBuild. Next, install Git. You will need to set the following specific options on install to ensure high performance:

• Configuring the line ending conversions must be: Checkout as-is, commit as-is

• Enable experimental built-in file system monitor

Install NodeJS on your system. This should also install chocolatey. If it does not, install it manually. To install the final two dependencies, run:

choco install make

You should be good to return back to the main Getting Started docs

Additional packages required for releasing

If you are creating binaries to target windows, you will need nsis (which mach calls makensisu for some reason, even though the binary is makensis):

choco install nsis

Note that you will also have to provide a path to nsis on your system. For mine it is:

export MAKENSISU="C:\\Program Files (x86)\\NSIS\\Bin\\makensis.exe"