Zig ELF Linker Improvements Devlog

Developers of the Zig programming language have announced significant improvements to the ELF linker in their latest update, enabling fast incremental compilation on Linux systems. This enhancement allows rebuilds of projects in milliseconds, which could greatly improve development workflows.

Matthew Lugg, a contributor to Zig, detailed that the new ELF linker, introduced in Zig 0.16.0, has advanced to support building the self-hosted Zig compiler with LLVM and LLD libraries enabled. This milestone demonstrates the linker’s increased capabilities, including the ability to perform incremental rebuilds without performance penalties, specifically on x86_64 Linux systems.

Recent tests show that developers can now perform quick rebuilds during debugging, with build times dropping to under 300 milliseconds in some cases. The current version still lacks support for generating DWARF debug information, which is a planned feature for future releases.

Why It Matters

This development is important because it directly impacts developer productivity by reducing build times dramatically. Fast incremental compilation allows for more efficient debugging, testing, and iteration, especially in large or complex codebases. It also signals ongoing improvements in Zig’s build system and toolchain, making the language more attractive for performance-critical or rapid development projects.

Background

The ELF linker improvements follow a series of recent updates to Zig’s build system and compiler infrastructure. Previously, the linker was limited to linking Zig-only code without external libraries, and only supported full rebuilds. The current enhancements are part of a broader effort to modernize Zig’s build process, including a reworked build system announced in late May 2026, which separates the build configuration from execution to speed up rebuilds and reduce redundant processing.

“The new ELF linker can now build the Zig compiler with LLVM and LLD enabled, and supports fast incremental rebuilds on Linux without extra overhead.”

— Matthew Lugg

“The build system rework reduces build times by isolating configuration and execution, enabling faster iteration for developers.”

— Andrew Kelley

What Remains Unclear

It is not yet clear when support for generating DWARF debug information will be implemented in the ELF linker. Additionally, broader compatibility with non-Linux platforms remains unconfirmed, and user reports on stability and performance are still emerging.

What’s Next

The Zig development team plans to complete DWARF debug info support for the ELF linker in upcoming updates. They will also continue testing the new features across different projects and platforms, with a focus on stability and performance benchmarks. A stable release incorporating these improvements is expected after further validation.

Key Questions

What is the main benefit of the new ELF linker in Zig?

The main benefit is enabling fast incremental compilation, allowing developers to rebuild projects in milliseconds, which improves debugging and development speed.

Does this update support debug information like DWARF?

No, support for generating DWARF debug info is currently missing but is planned as a future feature.

Is this feature available on all platforms?

Currently, the improvements are confirmed on x86_64 Linux systems. Support on other platforms has not yet been announced.

How can I try out these features now?

If you are using the master branch of Zig on Linux, you can enable incremental compilation with the new ELF linker by passing the appropriate flags, such as -fnew-linker and -fincremental.

Source: Hacker News