mozc/docs/build_mozc_in_windows.md

How to build Mozc in Windows

Summary

If you are not sure what the following commands do, please check the descriptions below and make sure the operations before running them.

python -m pip install six requests

git clone https://github.com/google/mozc.git
cd mozc\src

python build_tools/update_deps.py
python build_tools/build_qt.py --release --confirm_license
python build_mozc.py gyp
python build_mozc.py build -c Release package

# Install Mozc
out_win\Release\Mozc64.msi

Hint: You can also download Mozc64.msi from GitHub Actions. Check Build with GitHub Actions for details.

Hint: You can use Bazel to build Mozc (experimental). For details, please see below.

Setup

System Requirements

64-bit Windows 10 or later.

Software Requirements

Building Mozc on Windows requires the following software.

• Visual Studio 2022 Community Edition
  • Build Tools for Visual Studio 2022 should also work
• Python 3.9 or later with the following pip modules.
  • six
  • requests
• .NET 6 or later (for dotnet command).

For additional requirements for building Mozc with Bazel, please see below.

Install pip modules

python3 -m pip install six requests

Download the repository from GitHub

git clone https://github.com/google/mozc.git
cd mozc\src

Hereafter you can do all the operations without changing directory.

Check out additional build dependencies

python build_tools/update_deps.py

In this step, additional build dependencies will be downloaded.

• LLVM 19.1.7
• Ninja 1.11.0
• Qt 6.8.0
• .NET tools
• git submodules

You can skip this step if you would like to manually download these libraries.

Build

Build Qt

python build_tools/build_qt.py --release --confirm_license

If you would like to manually confirm the Qt license, drop --confirm_license option.

You can skip this process if you have already installed Qt prebuilt binaries.

Build Mozc

If you have built Qt in the above step, the following commands should be sufficient to build Mozc installers.

python build_mozc.py gyp
python build_mozc.py build -c Release package

If you want to build Mozc without Qt dependencies, specify --noqt option as follows. Note that mozc_tool.exe will be built as a mock version that does nothing if you specify --noqt.

python build_mozc.py gyp --noqt
python build_mozc.py build -c Release package

If you want to build Mozc with your own Qt binaries, specify --qtdir option as follows.

python build_mozc.py gyp --qtdir=<your Qt directory>
python build_mozc.py build -c Release package

If you need debug information, you can build debug version of Mozc as follows.

python build_mozc.py build_tools/build_qt.py --release --debug --confirm_license
python build_mozc.py build -c Debug package

Installers

You have release build binaries in out_win\Release\Mozc64.msi.

Clean up the Tree

To clean up the tree, execute the following. This will remove executables and intermediate files like object files, generated source files, project files, etc.

python build_mozc.py clean

Install Mozc

On a 64-bit environment, run the following command (or simply double click the corresponding file).

out_win\Release\Mozc64.msi

Uninstall Mozc

Press Win+R to open the dialog and type ms-settings:appsfeatures-app, or on terminal run the following command.

start ms-settings:appsfeatures-app

Then uninstall Mozc from the list.

---

Run unit tests

You can run unit tests as follows.

python build_mozc.py gyp --noqt
python build_mozc.py runtests -c Release

Note that you can specify --qtdir= option instead of --noqt in GYP phase since currently there is no unit test that depends on Qt.

---

Build with Bazel (experimental)

Additional requirements:

• Bazelisk
  • Bazelisk is a wrapper of Bazel to use the specific version of Bazel.
  • src/.bazeliskrc controls which version of Bazel is used.
• MSYS2

After running build_tools/update_deps.py and build_tools/build_qt.py, run the following command instead of build_mozc.py:

bazelisk --bazelrc=windows.bazelrc build --config oss_windows --config release_build package

You have release build binaries in bazel-bin\win32\installer\Mozc64.msi.

Tips for Bazel setup

• You do not need to install a new JDK just for Mozc.
• If you installed Bazel via Scoop, it is recommended to install MSYS2 via Scoop, too.

https://bazel.build/install/windows?hl=ja#install-compilers

---

Build with GitHub Actions

GitHub Actions are already set up in windows.yaml. With that, you can build and install Mozc with your own commit as follows.

1. Fork https://github.com/google/mozc to your GitHub repository.
2. Push a new commit to your own fork.
3. Click "Actions" tab on your fork.
4. Wait until the action triggered with your commit succeeds.
5. Download Mozc64.msi from the action result page if you are using 64-bit Windows.
6. Install Mozc64.msi.

Files in the GitHub Actions page remain available up to 90 days.

You can also find Mozc Installers for Windows in google/mozc repository. Please keep in mind that Mozc is not an officially supported Google product, even if downloaded from https://github.com/google/mozc/.

1. Sign in GitHub.
2. Check recent successfull Windows runs in google/mozc repository.
3. Find action in last 90 days and click it.
4. Download Mozc64.msi from the action result page if you are using 64-bit Windows.