Crate notalawyer_build 

Build-time generation of dependency license notices.

This crate is the build-script half of the notalawyer family. Called from a crate’s build.rs, it gathers the license texts of all dependencies (using the cargo_about library) and writes a single NOTICE file into OUT_DIR.

The other two crates consume that file at compile time and runtime:

• notalawyer-build (this crate) writes the NOTICE file from build.rs.
• notalawyer embeds it via include_notice!.
• notalawyer-clap exposes it behind a --license-notice CLI flag.

License acceptance and gathering are configured through an about.toml file, searched for from the consuming crate’s manifest directory upward; see cargo-about for its format.

Choosing a renderer

There are three entry points, in increasing order of control:

• build writes the built-in default format. This is all most crates need.
• build_with gathers the data, hands you a Notice, and writes whatever String your closure returns.
• try_build_with is the fallible variant for renderers (templating engines, etc.) that can fail.

gather is the lowest level: it returns a Notice and writes nothing, so you can inspect or serialize the data yourself. The Notice, License, UsedBy and Package types are owned and implement serde::Serialize, so you can feed them straight into your own templating engine without any of cargo-about’s lifetime-bound types leaking into your build script.

Example

Add notalawyer-build as a build dependency and call build from the main of your build.rs:

// build.rs
println!("cargo:rerun-if-changed=Cargo.toml");

notalawyer_build::build();

To customize the output, render a Notice yourself:

// build.rs
use std::fmt::Write as _;

notalawyer_build::build_with(|notice| {
    let mut out = String::new();
    for license in &notice.licenses {
        writeln!(out, "## {} ({})", license.name, license.id).unwrap();
        out.push_str(&license.text);
    }
    out
});

Structs

License

A single license text and the crates that use it.

Notice

A complete license notice: every distinct license text and the flat list of crates it was gathered from.

Package

An owned description of a single crate/package.

UsedBy

A single “crate uses this license” entry.

Enums

Error

An error from try_build_with.

Functions

build

Gather dependency licenses and write the NOTICE file into OUT_DIR using the built-in default format.

build_with

Gather licenses, render them with render, and write the result to $OUT_DIR/notalawyer.

gather

Gather dependency license data without writing anything.

try_build_with

Fallible variant of build_with for renderers that can fail (templating engines, etc.).