Environment Variables

RULES_PYTHON_ADDITIONAL_INTERPRETER_ARGS

This variable allows for additional arguments to be provided to the Python interpreter at bootstrap time when the bash bootstrap is used. If RULES_PYTHON_ADDITIONAL_INTERPRETER_ARGS were provided as -Xaaa, then the command would be:

python -Xaaa /path/to/file.py

This feature is useful for the integration of debuggers. For example, it would be possible to configure RULES_PYTHON_ADDITIONAL_INTERPRETER_ARGS to be set to /path/to/debugger.py --port 12344 --file, resulting in the command executed being:

python /path/to/debugger.py --port 12345 --file /path/to/file.py

See also

The interpreter_args attribute.

The guide on How to integrate a debugger

Added in version 1.3.0.

Changed in version 1.7.0: Support added for .

RULES_PYTHON_BOOTSTRAP_VERBOSE

When 1, debug information about bootstrapping of a program is printed to stderr.

RULES_PYTHON_BZLMOD_DEBUG

When 1, bzlmod extensions will print debug information about what they’re doing. This is mostly useful for development to debug errors.

RULES_PYTHON_DEPRECATION_WARNINGS

When 1, rules_python will warn users about deprecated functionality that will be removed in a subsequent major rules_python version. Defaults to 0 if unset.

RULES_PYTHON_ENABLE_PYSTAR

When 1, the rules_python Starlark implementation of the core rules is used instead of the Bazel-builtin rules. Note that this requires Bazel 7+. Defaults to 1.

Added in version 0.26.0: Defaults to 0 if unspecified.

Changed in version 0.40.0: The default became 1 if unspecified

RULES_PYTHON_ENABLE_PIPSTAR

When 1, the rules_python Starlark implementation of the PyPI/pip integration is used instead of the legacy Python scripts.

Added in version 1.5.0.

Changed in version 1.7.0: Flipped to be enabled by default.

RULES_PYTHON_EXTRACT_ROOT

Directory to use as the root for creating files necessary for bootstrapping so that a binary can run.

Only applicable when --venvs_use_declare_symlink=no is used.

When set, a binary will attempt to find a unique, reusable, location within this directory for the files it needs to create to aid startup. The files may not be deleted upon program exit; it is the responsibility of the caller to ensure cleanup.

Manually specifying the directory is useful to lower the overhead of extracting/creating files on every program execution. By using a location outside /tmp, longer lived programs don’t have to worry about files in /tmp being cleaned up by the OS.

If not set, then a temporary directory will be created and deleted upon program exit.

Added in version 1.2.0.

RULES_PYTHON_GAZELLE_VERBOSE

When 1, debug information from Gazelle is printed to stderr.

RULES_PYTHON_PIP_ISOLATED

Determines if --isolated is used with pip.

Valid values:

  • 0 and false mean to not use isolated mode

  • Other non-empty values mean to use isolated mode.

RULES_PYTHON_REPO_DEBUG

When 1, repository rules will print debug information about what they’re doing. This is mostly useful for development to debug errors.

RULES_PYTHON_REPO_DEBUG_VERBOSITY

Determines the verbosity of logging output for repo rules. Valid values:

  • DEBUG

  • FAIL

  • INFO

  • TRACE

RULES_PYTHON_REPO_TOOLCHAIN_VERSION_OS_ARCH

Determines the Python interpreter platform to be used for a particular interpreter (version, os, arch) triple to be used in repository rules. Replace the VERSION_OS_ARCH part with actual values when using, e.g., 3_13_0_linux_x86_64. The version values must have _ instead of . and the os, arch values are the same as the ones mentioned in the //python:versions.bzl file.

VERBOSE_COVERAGE

When 1, debug information about coverage behavior is printed to stderr.