rules_python
bzlmod
supportrules_python
: Yesrules_python_gazelle_plugin
: No (see below).In general bzlmod
has more features than WORKSPACE
and users are encouraged to migrate.
The releases page will give you the latest version number, and a basic example. The release page is located here.
Bazel supports external dependencies, source files (both text and binary) used in your build that are not from your workspace. For example, they could be a ruleset hosted in a GitHub repo, a Maven artifact, or a directory on your local machine outside your current workspace.
As of Bazel 6.0, there are two ways to manage external dependencies with Bazel: the traditional, repository-focused WORKSPACE system, and the newer module-focused MODULE.bazel system (codenamed Bzlmod, and enabled with the flag
--enable_bzlmod
). The two systems can be used together, but Bzlmod is replacing the WORKSPACE system in future Bazel releases. -- https://bazel.build/external/overview
We have two examples that demonstrate how to configure bzlmod
.
The first example is in examples/bzlmod, and it demonstrates basic bzlmod configuration. A user does not use local_path_override
stanza and would define the version in the bazel_dep
line.
A second example, in examples/bzlmod_build_file_generation demonstrates the use of bzlmod
to configure gazelle
support for rules_python
.
Under bzlmod, the default toolchain is no longer based on the locally installed system Python. Instead, a recent Python version using the pre-built, standalone runtimes are used.
If you need the local system Python to be your toolchain, then it‘s suggested that you setup and configure your own toolchain and register it. Note that using the local system’s Python is not advised because will vary between users and platforms.
If you want to use the same toolchain as what WORKSPACE used, then manually register the builtin Bazel Python toolchain by doing register_toolchains("@bazel_tools//tools/python:autodetecting_toolchain")
.
Note that using this builtin Bazel toolchain is deprecated and unsupported. See the {obj}runtime_env_toolchains
docs for a replacement that is marginally better supported. IMPORTANT: this should only be done in a root module, and may interfere with the toolchains rules_python registers.
NOTE: Regardless of your toolchain, due to #691, rules_python
still relies on a local Python being available to bootstrap the program before handing over execution to the toolchain Python.
To override this behaviour see {obj}--bootstrap_impl=script
, which switches to bash
-based bootstrap on UNIX systems.
On bzlmod
users have the option to use the bazel_downloader
to download packages and work correctly when host
platform is not the same as the target
platform. This provides faster package download times and integration with the credentials helper.
whl_library
reposDue to how bzlmod
is designed and the visibility rules that it enforces, it is best to use the targets in the whl
repos as they do not rely on using the annotations
API to add extra targets to so-called spoke
repos. For alternatives that should cover most of the existing usecases please see:
py_console_script_binary
to create entry_point
targets.whl_filegroup
to extract filegroups from the whl
targets (e.g. @pip//numpy:whl
)pip.override
to patch the downloaded whl
files. Using that you can change the METADATA
of the whl
file that will influence how rules_python
code generation behaves.