cargo-propagate-features

Cargo subcommand to automatically propagate workspace crate features to their dependencies.

What it does

For any crate A with feature X depending on crate B that also has feature X, this tool ensures that crate A's feature X includes "B/X" in its feature dependencies.

This ensures that when you enable a feature on a crate, all its dependencies that have the same feature also get that feature enabled. Without this, enabling a feature might not work correctly because dependencies don't have their corresponding features enabled.

Example

Consider a workspace with three crates:

• my-app depends on my-library and my-utils
• All three crates have the same features: backend, cli, desktop, web

When you enable the backend feature on my-app, you typically want the backend features of my-library and my-utils to also be enabled. This tool automatically adds those feature dependencies.

Before running the tool:

# my-app/Cargo.toml
[dependencies]
my-library = { path = "../my-library" }
my-utils = { path = "../my-utils" }

[features]
backend = []      # ❌ Doesn't enable backend features on dependencies
cli = []
desktop = []
web = []

After running the tool:

# my-app/Cargo.toml
[dependencies]
my-library = { path = "../my-library" }
my-utils = { path = "../my-utils" }

[features]
backend = ["my-library/backend", "my-utils/backend"]  # ✅ Now properly propagates
cli = ["my-library/cli", "my-utils/cli"]
desktop = ["my-library/desktop", "my-utils/desktop"]
web = ["my-library/web", "my-utils/web"]

Now when you build with cargo build --features backend, the backend features on my-library and my-utils will also be enabled.

Installation

Using cargo-binstall (Recommended)

First install cargo-binstall if you haven't already:

cargo install cargo-binstall

Then install cargo-propagate-features:

cargo binstall cargo-propagate-features

Using cargo install

cargo install cargo-propagate-features

Usage

From the workspace root:

cargo propagate-features [OPTIONS]

Options

• --dry-run: Show what would be changed without modifying files
• --features <FEATURES>: Comma-separated list of features to propagate (default: backend,cli,desktop,web)
• --workspace-path <PATH>: Path to workspace root or Cargo.toml (optional, defaults to workspace containing the manifest). When using cargo run, you can point to a Cargo.toml file directly.
• --quiet: Suppress output when there are no changes

The command automatically respects Cargo's standard options when installed and invoked via cargo:

• --manifest-path <PATH>: Path to Cargo.toml (automatically handled via cargo_metadata)
• --package <SPEC>: Work on a specific package (if supported)

License

MIT License - see LICENSE file for details.