Build Mode

Build Mode

Zig has four build modes:

Debug (default)
ReleaseFast
ReleaseSafe
ReleaseSmall

To add standard build options to a build.zig file:

build.zig

const Builder = @import("std").build.Builder;

pub fn build(b: *Builder) void {
    const exe = b.addExecutable("example", "example.zig");
    exe.setBuildMode(b.standardReleaseOptions());
    b.default_step.dependOn(&exe.step);
}

This causes these options to be available:

-Drelease-safe=[bool]

Optimizations on and safety on

-Drelease-fast=[bool]

Optimizations on and safety off

-Drelease-small=[bool]

Size optimizations on and safety off

Debug

Shell

$ zig build-exe example.zig

Fast compilation speed
Safety checks enabled
Slow runtime performance
Large binary size
No reproducible build requirement

ReleaseFast

Shell

$ zig build-exe example.zig -O ReleaseFast

Fast runtime performance
Safety checks disabled
Slow compilation speed
Large binary size
Reproducible build

ReleaseSafe

Shell

$ zig build-exe example.zig -O ReleaseSafe

Medium runtime performance
Safety checks enabled
Slow compilation speed
Large binary size
Reproducible build

ReleaseSmall

Shell

$ zig build-exe example.zig -O ReleaseSmall

Medium runtime performance
Safety checks disabled
Slow compilation speed
Small binary size
Reproducible build