Bazel vs Buck vs Pants: What are the differences?

Introduction

Bazel, Buck, and Pants are build tools used for building, testing, and deploying software. While they have similarities, there are several key differences between them. Below are the specific differences between Bazel, Buck, and Pants.

1. Build Language: Bazel uses a custom programming language called Starlark for build configuration, whereas Buck uses a JSON-like build language, and Pants uses a combination of YAML and Python. These different build languages provide varying levels of flexibility and ease of use.

2. Dependency Management: Bazel and Buck use a fine-grained dependency management system, which means the build system automatically tracks the dependencies of each individual target and only builds what is necessary. In contrast, Pants uses a coarse-grained dependency management system, which means all dependencies of a target are built together, regardless of whether they have changed or not. This can lead to longer build times in Pants compared to Bazel and Buck.

3. Performance: Bazel is known for its scalability and high performance, especially when dealing with large codebases. It has built-in caching and distributed build capabilities, allowing for faster and parallelized builds. Buck also has good performance but may not scale as well as Bazel for extremely large projects. Pants, on the other hand, focuses more on ease of use and developer productivity, sacrificing some performance optimizations.

4. Language Support: Bazel has built-in support for multiple programming languages, including Java, C++, Python, and more. It provides a consistent build experience across different languages and frameworks. Buck primarily focuses on providing excellent support for Java and Android projects. Pants, similar to Bazel, supports multiple languages, including Java, Scala, Python, and more.

5. Community and Adoption: Bazel is backed by Google and has gained significant traction in the industry, especially in large-scale projects and organizations. It has an active and growing community with a wealth of documentation and resources available. Buck, initially developed by Facebook, also has a dedicated community and is widely used in the mobile app development space. Pants, although less popular compared to Bazel and Buck, has a loyal following and is used by several companies and open-source projects.

6. Ease of Configuration: Bazel has a steep learning curve and requires a good understanding of its build language and concepts. It may take some time for developers to become proficient in configuring Bazel properly. Buck, on the other hand, has a simpler build language and is relatively easier to configure. Pants strikes a balance between the two, offering a more approachable configuration experience while still providing flexibility and powerful features.

In Summary, Bazel, Buck, and Pants differ in their build languages, dependency management systems, performance, language support, community adoption, and ease of configuration, catering to different needs and preferences in software development.