system-deps lets you write system dependencies in Cargo.toml metadata, rather than programmatically in build.rs. This makes those dependencies declarative, so other tools can read them as well.

For now only pkg-config dependencies are supported but we are planning to expand it at some point.

system-deps has been started as a fork of the metadeps project.

Usage

In your Cargo.toml, add the following to your [build-dependencies]:

system-deps = "1.1"

Then, to declare a dependency on testlib >= 1.2, a conditional dependency on testdata >= 4.5 and a dependency on glib-2.0 >= 2.64 add the following section:

[package.system-deps]
testlib = "1.2"
testdata = { version = "4.5", feature = "use-testdata" }
glib = { name = "glib-2.0", version = "2.64" }

In your build.rs, add:

fn main() {
    system_deps::Config::new().probe().unwrap();
}

Dependency versions can also be controlled using features:

[features]
v1_2 = []
v1_4 = ["v1_4"]

[package.system-deps]
gstreamer = { name = "gstreamer-1.0", version = "1.0", feature-versions = { v1_2 = "1.2", v1_4 = "1.4" }}

In this case the highest version among enabled features will be used.