Bazel 7 Release

DEC 12, 2023

Bazel 7 is now released. Bazel is Google's open source build system for fast and correct builds. It has built-in support for building both client and server software, including client applications for both Android and iOS platforms. It also provides an extensible framework that you can use to develop your own build rules. Bazel builds almost all Google products, including Google Search, GMail, and Google Docs.

What’s new in Bazel 7?

Bazel 7 is the latest major release on the long-term support (LTS) track. It includes:

Bzlmod: Bzlmod, Bazel's new modular external dependency management system, is now enabled by default (i.e. --enable_bzlmod defaults to true). If your project doesn't have a MODULE.bazel file, Bazel will create an empty one for you. The old WORKSPACE mechanism will continue to work alongside the new Bzlmod-managed system. Learn more about what’s changed since Bazel 6 and what’s coming up in Bazel 8 and 9.

Build without the Bytes (BwoB): Build without the Bytes for builds using remote execution is now enabled by default (i.e. --remote_download_outputs defaults to toplevel). Bazel will no longer try to download any intermediate outputs from the remote server, but only the outputs of requested top-level targets instead. This significantly improves remote build performance. Learn more about BwoB.

Merged analysis and execution (Skymeld): Project Skymeld aims to improve multi-target build performance by removing the boundary between the analysis and execution phases and allowing targets to be independently executed as soon as their analysis finishes.

Platform-based toolchain resolution for Android and C++: This change helps streamline the toolchain resolution API across all rulesets, obviating the need for language-specific flags. It also removes technical debt by having Android and C++ rules use the same toolchain resolution logic as other rulesets. Full details for Android developers are available in the Android Platforms announcement.

What's next?

Read the full release notes for Bazel 7, and follow along as we work together towards Bazel 8:

If you have any questions or feedback, or would like to share something you’ve built, reach out to product@bazel.build. We would love to hear from you!