anki/docs/development.md

Anki development

Packaged betas

For non-developers who want to try beta versions, the easiest way is to use a packaged version - please see:

https://betas.ankiweb.net/#/

Pre-built Python wheels

Pre-built Python packages are available on PyPI. They are useful if you wish to:

• Run Anki from a local Python installation without building it yourself
• Get code completion when developing add-ons
• Make command line scripts that modify .anki2 files via Anki's Python libraries

You will need Python 3.8 or 3.9 installed. If you do not have Python yet, please see the platform-specific instructions in the "Building from source" section below for more info.

Mac/Linux:

$ python3.8 -m venv ~/pyenv
$ ~/pyenv/bin/pip install --upgrade pip
$ ~/pyenv/bin/pip install aqt

Then to run Anki:

$ ~/pyenv/bin/anki

Windows:

c:\> python -m venv \pyenv
c:\> \pyenv\scripts\pip install --upgrade pip
c:\> \pyenv\scripts\pip install aqt

Then to run Anki:

c:\> \pyenv\scripts\anki

Building from source

Platform-specific instructions:

• Windows
• Mac
• Linux

Don't name the Git checkout ~/Anki or ~/Documents/Anki, as those folders were used on old Anki versions and will be automatically moved.

Before contributing code, please see Contributing.

If you'd like to contribute translations, please see https://translating.ankiweb.net/#/.

Building redistributable wheels

Run the following commands to create Python packages that can be redistributed and installed:

bazel build -c opt //pylib/anki:wheel
bazel build -c opt //qt/aqt:wheel

The generated wheel paths will be printed as the build completes.

You can then install them by copying the paths into a pip install command. Follow the steps in the "Pre-built Python wheels" section above, but replace the "pip install aqt" line with something like:

pip install /path/to/anki.whl /path/to/aqt.whl

Running tests

From inside the source folder:

bazel test //...

Pylint will currently fail if you're using Python 3.9.

Fixing formatting

If the format tests fail, most can be fixed by running format in the relevant package:

bazel run //rslib:format
bazel run //pylib:format
bazel run //qt:format
bazel run //ts:format
bazel run //pylib/rsbridge:format

If you're in one of those folders, you can use the short form:

bazel run format

Audio

Audio playing requires mpv or mplayer to be in your system path.

Currently pyaudio is not included as part of the build or the generated wheel requirements, so audio recording will not work when running in place. When installing the wheels, you can optionally install pyaudio as well.

On Linux/Mac, install the portaudio libs: (apt install portaudio19-dev / brew install portaudio), then pip install pyaudio.

On Windows, install the Python 3.8 wheel from https://github.com/ankitects/windows-ci-tools.

Recording also requires lame to be in your system path.

Tracing build problems

You can run bazel with '-s' to print the commands that are being executed.

Subcomponents

• pylib contains a Python module (anki) with the non-GUI Python code, and a bridge to the Rust code.
• qt contains the Qt GUI implementation (aqt).
• rslib contains the parts of the code implemented in Rust.
• ts contains Anki's typescript and sass files.

Environmental Variables

If ANKIDEV is set before starting Anki, some extra log messages will be printed on stdout, and automatic backups will be disabled - so please don't use this except on a test profile.

If LOGTERM is set before starting Anki, warnings and error messages that are normally placed in the collection2.log file will also be printed on stdout.

Cleaning

Unlike the old Make system, a "clean build" should almost never be required unless you are debugging issues with the build system. But if you need to get things to a fresh state, you can run bazel clean --expunge. Afte doing so, make sure you remove the ts/node_modules folder, or subsequent build commands will fail with a "no such file or directory node_modules/anki" message.

Mixing development and study

You may wish to create a separate profile with File>Switch Profile for use during development. You can pass the arguments "-p [profile name]" when starting Anki to load a specific profile.

If you're using PyCharm:

• right click on the "run" file in the root of the PyCharm Anki folder
• click "Edit 'run'..." - in Script options and enter: "-p [dev profile name]" without the quotes
• click "Ok"