Buck2 vs manypkg

Buck2 is a free build system from Meta for large-scale repositories that combine multiple programming languages. It uses Starlark rules, a dynamic dependency graph, and incremental actions to support extensible builds. Its language table lists prelude rules for C/C++, Erlang, Go, Haskell, Java, Kotlin, OCaml, Python, and Rust, though usability varies by language. Build actions can run remotely through services exposing Bazel's remote execution API; the project lists BuildBarn, BuildBuddy, EngFlow, and NativeLink as compatible with its distributed compilation support. Buck2 supports filesystem watching and can integrate with Meta's optional Eden virtual filesystem. Rules are hermetic by default and missing dependencies are errors, but local-only build steps are not sandboxed. The project describes Buck2 as early-stage and says it has no stable release tag; its latest binary tag changes with repository pushes. It warns that outside users may encounter rough edges, missing features, and missing toolchains. Source and binaries are available under MIT and Apache-2.0 licenses. The project directs users to GitHub for issue reports and offers a community Discord server.

manypkg is a command-line linter for package.json files in Yarn, npm, pnpm, Bun, and Lerna monorepos. It checks consistency across packages, including matching external dependency ranges, internal dependency ranges that include the referenced package version, and alphabetical ordering of dependencies. Other checks cover peer and development dependency relationships, root production dependencies, duplicate dependency types, package names, and repository fields. The `manypkg check` command runs repository checks, logs errors, and exits with a code. When a problem can be corrected automatically, `manypkg fix` can apply a fix. The CLI also runs package scripts with `manypkg run`, selecting a package by partial name or directory, and runs a command across packages with `manypkg exec`. The root package.json can configure ignored rules, the default branch, and workspace protocol behavior; the protocol setting defaults to `allow`. Installation is documented with `yarn add @manypkg/cli`. The tool is free and licensed under MIT. Thinkmill is its maker, based in Sydney, Australia; listed platforms are Linux, macOS, and Windows.