Buck2 vs EvoMaster

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.

EvoMaster automatically generates system-level tests for web and enterprise applications by fuzzing APIs. It targets REST, GraphQL, and RPC APIs, including gRPC and Thrift. Black-box testing works across implementation languages; white-box testing is available for APIs compiled to the JVM, such as Java and Kotlin. The tool evolves test cases using evolutionary algorithms, dynamic program analysis, and AI heuristics to improve measures such as code coverage and fault detection. Its project describes more than 30 fault-detection oracles, covering issues such as HTTP status problems, schema mismatches, BOLA, and SQL injection. Generated results can include JUnit 4 or 5 tests in Java or Kotlin, Python or JavaScript test suites, and an interactive HTML report by default. White-box testing supports PostgreSQL, MySQL, H2, and MongoDB communications and can generate database initialization. Authentication headers and cookies are supported, as is dynamic credential retrieval through configured login endpoints. EvoMaster is free, has no telemetry, and says it needs no external internet services beyond the application under test. It can run on Linux, macOS, Windows, or self-hosted; PyPI is the recommended installation route, with a JAR and Docker image also available.