Sean Vong-Karlage

This commit introduces a **new `runtime_libs` attribute** to **Buck2's native Python executable rules**, enabling the direct bundling of additional native libraries with the Python runtime. This **new capability** is defined in `prelude/decls/python_rules.bzl` and implemented in `prelude/python/python_binary.bzl` to ensure these libraries are included in the generated PAR file. The primary benefit is to facilitate proper loading of **Dynamic Shared Objects (DSOs)** by leveraging the RPATH mechanism within native Python executables, improving dependency management for complex Python applications. This allows for more robust and self-contained native Python builds.

This commit **enhances the Go build system** by standardizing the location for temporary files and ensuring a consistent build environment. It **configures the `go_wrapper`** in `go_bootstrap/tools/go/go_wrapper.go` to explicitly set the `TMPDIR` environment variable to `BUCK_SCRATCH_PATH`, resolving issues where temporary files might be created in inaccessible locations. Additionally, the `link` function in `prelude/go/link.bzl` is **refactored** to route the Go linker through `go_wrapper`, guaranteeing that all Go build steps operate with the same environment settings. This change **improves the reliability and consistency of Go builds** within the system by preventing build failures related to temporary directory access.

This commit introduces a **new capability** to the **`genrule`** rule by adding the `allow_offline_output_cache` parameter, enabling `genrule`s that access network resources to have their outputs cached for subsequent **offline builds**. The change involves updating the `genrule` declaration in `prelude/decls/core_rules.bzl` and its implementation in `prelude/genrule.bzl` to pass this new attribute to the underlying action. Comprehensive documentation for the parameter has been added, alongside a dedicated test prelude and **integration tests** in `tests/core/trace_io/` to verify the new offline caching behavior. This enhancement significantly improves the **offline build experience** for projects utilizing network-dependent `genrule`s.

This commit introduces a **new feature** to the **Buck2 action implementation**, enabling **offline output caching for `run` actions**. It exposes an `allow_offline_output_cache` parameter on the `actions.run()` Starlark function, which, when enabled, instructs the system to copy action outputs to an offline cache during tracing builds and restore them during offline builds. This enhancement allows `run` actions to function seamlessly within the **offline build system** by eliminating network dependencies for their cached outputs. The change primarily affects the `buck2_action_impl` module, with core logic implemented in `app/buck2_action_impl/src/actions/impls/run.rs` and the parameter added in `app/buck2_action_impl/src/context/run.rs`. Comprehensive new tests in `tests/core/trace_io` validate the cache population and restoration behavior.

This commit **refactors** the `merge_manifest` tool, **rewriting its implementation from Python to Rust**. This change, primarily affecting the **`buck2_offline_archive`** component, aims to improve **type safety** and ensure **consistency** with other tools in the directory. The new Rust version efficiently merges, deduplicates, and sorts offline build tracing manifests by reusing existing types and leveraging `BTreeSet` for ordered output. Comprehensive **inline tests** have been added, and the `buck2_offline_archive/src/lib.rs` file was updated to derive necessary traits for proper sorting.

This commit **refactors** the **`buck2_server`'s `trace-io` subsystem** to ensure **deterministic output** for the `export-manifest` command. It modifies the `build_response_with_trace` function in `app/buck2_server/src/trace_io.rs` to sort all manifest lists, including `paths`, `external_paths`, `relative_symlinks`, and `external_symlinks`, alphabetically. Symlinks are specifically sorted by their link field for intuitive ordering. This **maintenance** change improves the reliability and predictability of the `trace-io` output, making it easier for downstream tools to consume and compare results consistently.

This commit introduces a **new capability** to the **offline cache restoration API**, allowing the `declare_copy_from_offline_cache` function to accept a slice of `BuildArtifact`s instead of a single one. This **enhancement** within the **`buck2_action_impl`** module enables actions that produce multiple outputs to be restored from the offline cache in a single, atomic operation. The updated API now enforces **all-or-nothing semantics**, returning an error if any of the requested outputs are missing from the cache. This change improves the efficiency and reliability of cache restoration for multi-output actions, ensuring data integrity and streamlined processing.

This commit **introduces a new capability** to the **Buck2 Python build system** by exposing the `par_style` attribute within the `PythonLibraryInfo` provider. The `create_python_library_info` function in `prelude/python/python_library.bzl` is updated to accept and pass this parameter, which is then propagated from the build context when creating **Python executables** via `python_executable` in `prelude/python/python_binary.bzl`. This **feature enhancement** allows downstream rules and tools consuming `PythonLibraryInfo` to access and utilize the PAR style information. This enables more precise control over Python packaging and execution, impacting how Python libraries and binaries are built and consumed.

This commit **enhances the `check_dependencies_test` framework** in Buck2 by **adding support for target modifiers**, enabling more precise dependency validation. This new capability allows developers to assert that targets built with specific configurations do not inadvertently pull in incorrect versions of third-party libraries. Additionally, the `target_deps()` filter within the `check_dependencies_test.bxl` script is now **optional**, restoring flexibility similar to older dependency audit tools. These **enhancements** to the `tests/` module's dependency checking mechanism, affecting `check_dependencies_test.bzl` and `test_bxl_check_dependencies_template.py`, provide a more robust and configurable way to analyze target dependencies.

This commit **improves the developer experience** within the **`buck2` build system** by enhancing the clarity of **dependency check error messages**. It modifies the `tests/check_dependencies_test.bxl` script to print banned or blocklisted dependencies one per line, making the diagnostic output much easier to parse. This **maintenance** change introduces a helper function specifically for formatting these error messages. Developers debugging dependency issues will now find it significantly easier to identify and resolve problematic dependencies, streamlining their workflow.

This commit **enhances** the `buck2` build system by modifying the **Rust deferred linking action** (`deferred_link_action.py`). It now leverages the `BUCK_SCRATCH_PATH` environment variable to specify the directory for creating temporary files. This **feature improvement** ensures that temporary files are more readily available and consistently located across both local and remote build environments. The change primarily impacts the **Rust build process**, improving its compatibility and reliability by standardizing temporary file locations.

This commit provides a **bug fix** to the **C++ symbol extraction process**, specifically within the `prelude` module's `symbols.bzl` configuration. It prevents the stripping of the weak symbol `_ZTHN3c104impl26raw_local_dispatch_key_setE`, which previously caused it to be incorrectly promoted to an undefined symbol. By adding a new `sed` command, this **maintenance** change resolves **linker errors** that would otherwise occur during compilation, ensuring the symbol retains its weak status. This improves the robustness of the build system by correctly handling specific weak symbol definitions.

This commit introduces **CUDA library support** to the **Antlir distribution platform**, making these libraries available as build-time dependencies for CUDA-dependent binaries. It specifically configures support for CUDA versions 12.4 and 12.8, utilizing `select` logic to manage version and architecture placeholders. As a **new capability**, this change ensures hermeticity by bundling CUDA libraries directly into packaged artifacts, which will **increase binary size and startup time** but facilitates testing in environments without GPU passthrough. Additionally, the `_is_select` function is now exposed in `prelude/utils/selects.bzl` to support this integration.

This commit **fixes a build-time linking issue** by adding `MallocExtension_Internal_GetNumericProperty` to the **C++ symbol filter list** defined in `prelude/cxx/symbols.bzl`. This specific symbol, which is a weak symbol, was causing **missing symbol errors** when incorrectly promoted during **omnibus linking** by **Antlir's upstream linker**. The change ensures that the symbol is properly filtered out during symbol extraction, preventing build failures for projects that rely on Antlir's linking process. This is a **maintenance update** to the build system's symbol handling to improve linking robustness.

This commit performs **toolchain maintenance** by **upgrading the GCC toolchain** to `gcc-toolset-14` for `platform010`, resolving `libstdc++` symbol mismatches that caused linker errors. It also includes a **refactoring** of the **linking process** within `prelude/linking/link_info.bzl`, specifically in `append_linkable_args`. This **fixes a build issue** by ensuring that the entire `.so` extension is correctly stripped from library names when sonames are not extracted, preventing incorrect linker flags like `-lgcc_s.so`. This change enables successful compilation and linking with newer GCC versions, particularly for the `platform010` environment.

This commit **fixes a build issue** affecting **TEE builds** by preventing specific linker errors. It **excludes** the `_ITM_deregisterTMCloneTable`, `_ITM_registerTMCloneTable`, and `__gmon_start__` symbols from the undefined symbols listing within `prelude/cxx/symbols.bzl`. This change addresses a problem where the CentOS linker incorrectly promoted these weak symbols to strong weak, leading to build failures. By updating the **linker configuration**, this ensures these symbols are properly handled, allowing **TEE builds** to complete successfully.

This commit introduces a **new capability** for the `buck2 debug chrome-trace` command, allowing users to specify a `--trace-id` directly. This enhancement to the **Buck2 client's debugging tools** enables the command to download and process chrome traces from a given ID, eliminating the need to first materialize the trace file locally. The `ChromeTraceCommand` in `app/buck2_client/src/commands/debug/chrome_trace.rs` was refactored to leverage `EventLogOptions` for this improved log retrieval, streamlining the analysis of remote or non-locally generated traces. This significantly improves the convenience and efficiency of debugging builds by simplifying trace acquisition.

This commit implements a **bug fix** for the **Buck2 remote execution (RE) subsystem**, addressing an issue where the `remote_execution_dynamic_image` attribute was not being correctly applied. Previously, an incorrect conditional check in `prelude/tests/re_utils.bzl` prevented this crucial configuration from being set on `CommandExecutorConfig` instances. The change removes this faulty conditional logic within the `get_re_executors_from_props` function, ensuring that the specified dynamic image is always properly configured. This guarantees that custom remote execution environments are now correctly utilized when expected, resolving an unexpected behavior for users relying on specific RE images.

This commit introduces a **new capability** to the **ROCm build system** by adding a `hip_toolchain_override` mechanism. This allows C/C++ source files, even those not ending in `.hip`, to be compiled using the ROCm toolchain by explicitly configuring `hip_compiler_info` instead of `cxx_compiler_info`. The change primarily affects the **toolchain override logic** and includes modifications to `prelude/cxx/archive.bzl` to support the `amdclang` archiver type in archive functions. This enhancement provides greater flexibility for building ROCm-related projects and aims to streamline future linking processes by potentially replacing `hip_link` actions with standard `cxx_library` rules.

This commit implements a **compatibility fix** within the **remote execution utilities** (`prelude/tests/re_utils.bzl`) by conditionally setting the `remote_execution_dynamic_image` attribute. The `get_re_executors_from_props` function now checks for the attribute's presence in `CommandExecutorConfig` before applying it. This **maintenance** change addresses an issue where older, pinned Buck2 versions, specifically those used by ASIC, would fail due to their lack of support for this newer attribute. The modification ensures that projects relying on these older Buck2 versions can continue to build without disruption, preventing regressions for specific user groups.