Build values

Build values provide application metadata such as versions, release channels, and build numbers without relying on generated Go names or linker flags.

Declare values

Declare values in the root project’s ard.toml:

[build.values]
version = { type = "Str", default = "dev", release = true }
release_channel = { type = "Str", default = "local" }
build_number = { type = "Int", default = 0 }
experimental = { type = "Bool", default = false }

Build value names must be valid Ard identifiers. Supported types are Str, Int, and Bool. Every value requires a default, which is used by ordinary builds, ard check, ard run, ard test, and editor tooling.

Import the compiler-provided ard/build module to read the values:

use ard/build

fn version() Str {
  build::version
}

Build values are immutable. They belong to the root application; dependencies cannot read the application’s values.

Override values

Pass an override for each value that release tooling supplies:

ard build main.ard \
  --define version=v1.2.3 \
  --define release_channel=stable \
  --define build_number=42 \
  --out example

Str values use all text after the first = and may be empty or contain more = characters. Bool accepts exactly true or false. Int accepts signed decimal values.

Unknown values, duplicate overrides, and values with the wrong type are errors.

Release requirements

A declaration with release = true must have an explicit override when building with --release:

ard build main.ard --release --define version=v1.2.3

The default does not satisfy this requirement, even when the value is unused. An explicit override equal to the default does satisfy it. --release only enforces this policy; it does not change optimization or target settings.

Ard does not inspect environment variables, Git state, timestamps, or hostnames. Release tooling should collect that metadata and pass it explicitly.