Zig: Build System Reworked

Zig has implemented a major rework of its build system and introduced an advanced ELF linker supporting fast incremental compilation, significantly improving build performance for users on x86_64 Linux.

On May 26, 2026, Zig announced a new build system architecture that separates the configuration process from the build execution. The previous approach compiled the entire build process into a single, monolithic process, which was slower and less flexible. The new system compiles build.zig files into a small, debug-mode process called the “configurer,” which constructs a build graph and serializes it into a binary file. Meanwhile, the “maker” process, compiled once per Zig version and cached globally, asynchronously executes the build graph based on the serialized configuration, enabling faster rebuilds.

Alongside this, Zig revealed a new ELF linker, initially supporting only Zig code but now capable of building the self-hosted Zig compiler with LLVM and LLD. The key feature of this linker is its support for fast incremental rebuilds on x86_64 Linux, allowing developers to rebuild projects in milliseconds, even when linking external libraries or C sources. Despite still lacking DWARF debug information support, this feature is expected to significantly enhance debugging workflows and iterative development.

Why It Matters

These updates are important because they address long-standing performance bottlenecks in Zig’s build process, especially for large or complex projects. Faster rebuilds enable more efficient development cycles, particularly in debugging and testing phases. The separation of build configuration and execution also lays the groundwork for future feature expansion without compromising build speed, making Zig more competitive as a systems programming language.

Background

Prior to this update, Zig’s build system compiled all build logic into a single process, which could become slow as projects grew. The new architecture, introduced in May 2026, aligns with similar practices in other build tools to improve speed and modularity. The ELF linker development, ongoing since Zig 0.16.0, has progressed from initial support for Zig-only linking to a more capable system that supports incremental builds, with the major milestone announced in late May 2026. These developments follow the language’s broader efforts to enhance performance and developer experience.

“The new build system reduces rebuild times significantly, especially when using –watch or –fuzz, by only compiling the necessary parts.”

— Andrew Kelley

“The ELF linker now supports fast incremental rebuilds on x86_64 Linux, enabling rebuilds in milliseconds, which is a game-changer for debugging.”

— Matthew Lugg

What Remains Unclear

It is not yet clear when the DWARF debug information support will be implemented in the ELF linker, or how broadly the new build system will be adopted across all project types. Further testing and user feedback are expected to refine these features.

What’s Next

Next steps include integrating DWARF support into the ELF linker, expanding testing across different platforms, and preparing for the upcoming Zig 0.17.0 release. Developers are encouraged to try out the new build system and linker features on the master branch and report issues.

Key Questions

When will DWARF debug information support be available in the ELF linker?

The development team has prioritized this feature but has not yet announced an exact release date. It is expected in future updates following initial stability testing.

Can I use the new build system with existing projects?

Most likely yes, especially if your project is on the master branch. However, users should test compatibility and report any issues.

Will these updates be included in the upcoming Zig 0.17.0 release?

The build system rework and ELF linker improvements are expected to be part of Zig 0.17.0, which is scheduled for release soon after these developments.

Are there any performance benchmarks available?

Yes, early benchmarks indicate that rebuild times can be reduced from around 36 seconds to under 300 milliseconds when using incremental builds with the new linker.

Source: Hacker News