Environment Variables

::::{envvar} 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

:::{seealso} The {bzl:obj}interpreter_args attribute.

The guide on {any}How to integrate a debugger :::

:::{versionadded} 1.3.0 ::: :::{versionchanged} 1.7.0 Support added for {bzl:flag}--bootstrap_impl=system_python. :::

::::

:::{envvar} RULES_PYTHON_BOOTSTRAP_VERBOSE

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

:::{envvar} 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. :::

:::{envvar} 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. :::

::::{envvar} 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 {bzl:flag}--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.

:::{versionadded} 1.2.0 ::: ::::

:::{envvar} RULES_PYTHON_GAZELLE_VERBOSE

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

:::{envvar} 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. :::

:::{envvar} RULES_PYTHON_PYCACHE_DIR

Determines the directory that runtime-generated pyc cache files will be stored in.

This directory may be reused between invocations, depending on the sandboxing configuration. Setting it to /dev/null will, in effect, disable runtime pyc caching. By setting e.g. --sandbox_add_mount_pair=/tmp/rules_python_pycache, it's possible for pyc caching to persist across invocations.

Behavior specific to downloaded runtimes: First RULES_PYTHON_PYCACHE_DIR is checked. If set, it is used as-is for the root pycache directory.

Otherwise, the following environment variables are checked in the following order. Their values will have rules_python_pycache appended to them to form the root pycache directory:

1. XDG_CACHE_HOME.
2. TMP (non-Windows) or TEMP (Windows).
3. The common platform-specific temporary directory (/tmp (non-Windows) or C:\Temp (Windows)).

If such a diretory cannot be found, or created, then /dev/null will be used, which will effectively disable pyc caching.

:::

:::{envvar} 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. :::

:::{envvar} RULES_PYTHON_REPO_DEBUG_VERBOSITY

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

• DEBUG
• FAIL
• INFO
• TRACE :::

:::{envvar} 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. :::

:::{envvar} VERBOSE_COVERAGE

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

Removed Environment Variables

:::{versionremoved} 2.1.0 The following environment variables were removed:

• RULES_PYTHON_ENABLE_PYSTAR: Used to enable the Starlark implementation of core rules.
• RULES_PYTHON_ENABLE_PIPSTAR: Used to enable the Starlark implementation of PyPI integration. :::