Kasra Ghodsi

This commit **refactors** the **Buck2 prelude's Python test runner** by removing an **always-true Python 2.6 version guard** from the `run_tests` method in `prelude/python/tools/__test_main__.py`. The condition `if sys.version_info[0] > 2 or sys.version_info[1] > 6:` was redundant as it always evaluated to `True` in Python 3.x environments, causing `unittest.installHandler()` to execute unconditionally. This **maintenance cleanup** streamlines the codebase by eliminating dead code and legacy Python 2 artifacts, aligning with the project's Python 3.10+ support. It mirrors a similar fix applied to `fbcode/python/__fb_test_main__.py`, contributing to a broader effort to remove Python 2 remnants.

This commit introduces a **new capability** to the **Python package build system** by **passing resolved bytecode artifact paths** to the **Rust builder** (`rust_make_par`). It modifies `prelude/python/make_py_package.bzl`, specifically within the `_make_py_package_live` logic, to ensure these paths are correctly supplied. This **enhancement** enables the Rust builder to perform content hash replacement on these artifacts, serving as a crucial **maintenance** step to prevent build failures from unknown command-line arguments and facilitate the broader adoption of Rust-based Python package compilation.

This commit **fixes a rollout issue** preventing **content-based path hashing** from being correctly applied to `python_library` targets during compilation. Previously, the rollout flag was only configured for `python_binary` rules, causing `python_library` targets to incorrectly bypass this optimization. By adding the `supports_pyc_content_based_paths` attribute to the `python_library` rule definition in `prelude/decls/python_rules.bzl`, this change ensures that content-based path hashing is properly enabled for all relevant Python compilation paths. This **enables a critical optimization** for `python_library` builds, ensuring consistent and correct behavior across the Python ecosystem.

This commit **fixes a critical incompatibility** within the **Python packaging system** related to content-based paths and gradual rollouts. Previously, `output_artifacts` string replacement was conditionally applied, leading to issues when a `python_binary` (config-based hashing) consumed a `python_library` (content-based hashing) during a directory-based rollout. To resolve this, the change **removes the conditional gating** in `prelude/python/make_py_package.bzl` and `prelude/python/tools/make_py_package_modules.py`, ensuring that `bytecode_artifacts` are always passed and processed. This **maintenance improvement** guarantees that placeholder string replacement is consistently performed, thereby preserving the ability to safely conduct **gradual rollouts** across different hashing configurations.

This commit performs a **cleanup and refactoring** of the **Python package creation tools** within `prelude`, specifically targeting the removal of deprecated `inplace_lite` infrastructure. It **removes the `--template-lite` argument** from `make_py_package_inplace.py` and its associated `export_file` rule from the `BUCK` build configuration, as this package style is no longer supported. Additionally, docstring references in `make_py_package_inplace.py` and `make_py_package_modules.py` are updated to correctly point to `run_inplace.py.in`. This change streamlines the codebase by eliminating dead code and outdated references, ensuring consistency with the removal of the `inplace_lite` package style.

This commit performs **maintenance** by **removing the deprecated `--use-lite` CLI argument** from the **PAR packaging tools**. It updates `prelude/python/tools/make_py_package_inplace.py` to eliminate the argument parsing and conditional template selection logic within `parse_args` and `write_bootstrapper`, ensuring the bootstrapper now unconditionally uses the full `run_inplace.py.in` template. Additionally, the `--use-lite` option is removed from `fbcode/tools/make_par/buck.py`, which serves as a Buck v2 compatibility shim. This **cleanup** streamlines the **Python packaging process** by removing a no-longer-emitted option, contributing to the deprecation of the `inplace_lite` package style.

This commit **removes all references and associated logic for the deprecated `inplace_lite` Python package style** from the `prelude` module. It updates `prelude/decls/python_common.bzl` to remove `inplace_lite` from valid package styles and refactors `_make_py_package_impl` and `_pex_bootstrap_args` in `prelude/python/make_py_package.bzl` to eliminate its handling. This is a **cleanup and refactoring** effort that simplifies the **Python build system's internal configuration and package creation logic**. As no targets were utilizing `inplace_lite`, this change has no functional impact on existing builds.

This commit **prepares the Buck2 Python package creation system** by copying placeholder string replacement logic from `make_par/buck.py` to `prelude/python/tools/make_py_package_modules.py`. Specifically, it introduces `create_pyc_hash_dict` and `replace_pyc_hash_placeholder` functions and updates argument parsing within `make_py_package_modules.py`. This **maintenance** change is a **prerequisite for a future bug fix** that will extend content-based path handling to inplace builds. The ultimate goal is to resolve **Content-Addressable Filesystem (CAF) build failures** by enabling proper `output_artifacts` string replacement in all build types. While currently a no-op, this lays essential groundwork for an upcoming change.

This commit **removes an `inplace` restriction** within the **content-based path placeholder string replacement logic**, building upon prior foundational work. It now consistently passes `bytecode_artifacts` regardless of the package style, which is essential for correctly processing **all Python binary cases**. This **enhancement** specifically **fixes issues in CAF builds** that previously failed when content-based path hashing was enabled without proper placeholder string replacement, thereby **improving the robustness and reliability of Python artifact generation**.

This commit introduces a **new capability** to enable **content-based output path addressing** for Python bytecode, aiming to **deduplicate build artifacts** when BUCK configurations change but the output remains identical. It adds a `supports_pyc_content_based_paths` attribute to the **Python executable rule definition** in `prelude/decls/python_rules.bzl`. The **Python compilation and PEX module generation logic** in `prelude/python/compile.bzl` and `prelude/python/make_py_package.bzl` are updated to respect this new attribute. This feature is initially **rolled out only for Python binaries within the `fbcode//python` directory** to mitigate build failure risks, improving overall build stability and efficiency.

This commit **enables content-based output path addressing for Python bytecode** by resolving a critical issue in the packaging step. Previously, `output_artifacts` placeholders in the bytecode manifest were not replaced with actual content hashes, causing build failures when content-based hashing was active. The change in `prelude/python/make_py_package.bzl` now passes bytecode artifacts to the packaging process, allowing the system to **fetch and substitute the resolved content hash** for the placeholder. This **feature enablement** ensures correct path resolution, leading to increased cache hits for `py_compile` actions and more efficient builds, despite a minor increase in overall execution time.

This commit performs a **refactoring** by **removing redundant validation** within the **Python toolchain**'s `make_py_package` function in `buck2/prelude/python/toolchain.bzl`. Specifically, it eliminates an unnecessary check for `package_style` enum values, as the `get_package_style` function already ensures valid enum creation, causing a build failure if an invalid value is provided. This **code cleanup** improves the maintainability and efficiency of the Python package generation logic without altering its functional behavior or introducing any breaking changes.

This commit **refactors** the **Python packaging logic** within `prelude/python/make_py_package.bzl` to generalize how package style information is passed. The internal functions `_make_py_package_impl` and `_pex_modules_args` now accept a more descriptive `PackageStyle` enum instead of a boolean `standalone` parameter. This **generalization** enables more precise checks for specific package styles, such as `inplace`, further down the build stack. The change improves the flexibility and expressiveness of the **Python build system's internal API** for handling various package configurations.

This commit **fixes a bug** in the **Python toolchain's compile actions** by correctly propagating the content-based output path flag. Previously, a `None` value from the toolchain's configuration could be passed to the `declare_output()` function, leading to runtime errors due to an expected non-null boolean. The change in `prelude/python/compile.bzl`, specifically within `compile_manifests_for_mode`, now explicitly checks if the toolchain's content-based path field is `True`, passing `False` otherwise. This **stabilizes the rollout** of **content-based output path addressing for Python bytecode**, preventing build failures and ensuring the feature can function reliably.

This commit **prepares the Python compilation pipeline** by piping the `supports_content_based_paths` flag from the **Python toolchain** to the `declare_output` action within the `compile_manifests_for_mode` function in `prelude/python/compile.bzl`. This **feature enablement** is a foundational step towards enabling content-based output path addressing for Python bytecode. While this change introduces the flag, it currently has **no immediate behavioral impact** as the parameter remains hard-coded to `False`, setting the stage for future functionality.

This commit **introduces a new configuration flag** to the **Python toolchain definition**, adding a `supports_content_based_paths` boolean field to the `PythonToolchainInfo` provider in `prelude/python/toolchain.bzl`. This **preparatory change** lays the groundwork for enabling **content-based output path addressing for Python bytecode**, which will allow future compile actions to utilize content hashing for output paths. While currently a no-op and hardcoded to `False`, this addition is a **foundational step** towards a more robust and efficient Python build system. It represents a **new capability** for the Python build infrastructure, setting the stage for future improvements in output management.