Bazel vs Pants: What are the differences?
Developers describe Bazel as "Correct, reproducible, fast builds for everyone". Bazel is a build tool that builds code quickly and reliably. It is used to build the majority of Google's software, and thus it has been designed to handle build problems present in Google's development environment. On the other hand, Pants is detailed as "Build system by Twitter, Foursquare, and Square". Pants is a build system for Java, Scala and Python. It works particularly well for a source code repository that contains many distinct projects.
Bazel and Pants can be primarily classified as "Java Build" tools.
Some of the features offered by Bazel are:
- Multi-language support: Bazel supports Java, Objective-C and C++ out of the box, and can be extended to support arbitrary programming languages.
- High-level build language: Projects are described in the BUILD language, a concise text format that describes a project as sets of small interconnected libraries, binaries and tests. By contrast, with tools like Make you have to describe individual files and compiler invocations.
- Multi-platform support: The same tool and the same BUILD files can be used to build software for different architectures, and even different platforms. At Google, we use Bazel to build both server applications running on systems in our data centers and client apps running on mobile phones.
On the other hand, Pants provides the following key features:
- Builds Java, Scala, and Python.
- Adding support for new languages is straightforward.
- Supports code generation: thrift, protocol buffers, custom code generators.
"Fast" is the top reason why over 18 developers like Bazel, while over 5 developers mention "Creates deployable packages" as the leading cause for choosing Pants.
Bazel and Pants are both open source tools. It seems that Bazel with 12.2K GitHub stars and 2K forks on GitHub has more adoption than Pants with 1.15K GitHub stars and 328 GitHub forks.