feat(toml): Parse support for multiple build scripts #15630

namanlp · 2025-06-04T20:37:25Z

Hi Everyone!

This is PR for the manifest parsing of the first milestone of GSoC Project : Build Script Delegation

What does this PR try to resolve?

Currently, just a single build script is allowed for each package. This PR will allow users to create and use multiple build scripts, and is backward compatible with single script as well as boolean values.

Motivation : This will help users to maintain separate smaller and cleaner build scripts instead of one large build script. This is also necessary for build script delegation.

Open questions:

What should the build script target names be?
- Currently they use the file stem of the build script which could run into conflicts

Known Issues:

This is just parsing support, and currently, only the first build script of the array is actually executed.

How to test and review this PR?

There is a feature gate multiple-build-scripts that can be passed via cargo-features in Cargo.toml. So, you have to add

cargo-features = ["multiple-build-scripts"]

Preferably on the top of the Cargo.toml and use nightly toolchain to use the feature

This PR is ready to be reviewed and merged

epage · 2025-06-04T20:50:23Z

Feel free to rebase on master, rather than merge it.

crates/cargo-util-schemas/src/manifest/mod.rs

src/cargo/core/features.rs

crates/cargo-util-schemas/src/manifest/mod.rs

src/cargo/ops/vendor.rs

src/cargo/util/toml/mod.rs

src/cargo/core/features.rs

src/cargo/util/toml/mod.rs

src/cargo/util/toml/targets.rs

epage · 2025-06-12T20:04:22Z

src/cargo/util/toml/targets.rs

+        if custom_build.len() > 1 {
+            anyhow::bail!("multiple build scripts feature is not implemented yet! ")
+        }
+        let custom_build = Path::new(&custom_build[0]);
        let name = format!(
            "build-script-{}",
            custom_build


We'll need to loop over

Do we need to make build script names more unique?

src/doc/src/reference/unstable.md

src/cargo/util/toml/mod.rs

rustbot · 2025-06-19T21:51:31Z

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namanlp · 2025-06-19T21:54:02Z

r? @epage

epage · 2025-06-20T20:41:06Z

src/doc/src/reference/unstable.md

+## Multiple Build Scripts
+* Original Pull Request: [#15630](https://github.com/rust-lang/cargo/pull/15630)


Let's use #14903 as the tracking issue. Please link to it from here

Should I also mention about GSoC?

…schema.json

… nightly)

rustbot added the A-unstable Area: nightly unstable support label Jun 4, 2025

rustbot added A-manifest Area: Cargo.toml issues Command-vendor labels Jun 5, 2025

epage reviewed Jun 5, 2025

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epage reviewed Jun 5, 2025

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namanlp closed this Jun 6, 2025

namanlp force-pushed the multiple-build-scripts-1 branch from 60fe887 to f6bebc3 Compare June 6, 2025 21:16

namanlp reopened this Jun 6, 2025

namanlp force-pushed the multiple-build-scripts-1 branch 2 times, most recently from b7a6036 to 1d18b6b Compare June 8, 2025 22:09