SYSTEM Cited by 1 source

Buck2

What it is

Buck2 is Meta's large-scale open-source build system (the Rust-based successor to the original Buck). It is the build system for Meta's monorepo and was open-sourced in April 2023 — see the Buck2 announcement. It supports fine-grained hermetic action-graph-based builds, remote-execution, and parametric target definitions.

Seen in

• sources/2026-04-09-meta-escaping-the-fork-webrtc-modernization — Buck is used as the build-graph primitive for handling injected WebRTC-internal components that can't be shimmed source-level ("shimming these components would mean proxying WebRTC against itself"). Instead, Meta uses Buck target duplication plus C++ macros to dynamically change namespaces at build time, duplicate the high-level build target, and expose symbols for both flavors through a single header. The build-system-level answer to "I need two copies of this component's symbols, one per WebRTC flavor" — more surgical than source duplication, avoids the shim-against-itself problem.

Related

• systems/meta-webrtc-shim — the WebRTC shim that leverages Buck's target-duplication for injected components.
• concepts/build-graph — the fundamental abstraction Buck operates on.
• concepts/hermetic-build — a Buck design property Meta leverages for reproducibility.
• concepts/monorepo — Buck's natural habitat.