This repository provides a centralized management system for Rust crate dependencies using Bazel's crate_universe.

The SCORE Crates repository implements a streamlined approach for Rust crate dependencies that:

• Defines crates directly in MODULE.bazel using crate.spec()
• Uses rules_rust crate_universe for dependency resolution
• Provides convenient aliases via auto-generated BUILD file
• Automatically syncs aliases with @crate_index targets

When multiple Bazel modules depend on each other and both pull in Rust crates via rules_rust, Bazel pulls in the same crate multiple times. This leads to name clashes in the Rust compiler, even when using identical versions.

    Module A                    Module B
    ├── crate.spec(serde)       ├── crate.spec(serde)
    └── @crate_index_a//:serde  └── @crate_index_b//:serde
                    ↘                     ↙
                      Your Application
                    (💥 Name clash: two different serde crates!)

              SCORE Crates Module
              ├── crate.spec(serde)
              └── @crate_index//:serde
                       ↙        ↘
            Module A              Module B
            (uses SCORE)          (uses SCORE)
                  ↘                ↙
                  Your Application
               (✅ Single serde crate!)

• Eliminates duplicate crates: Only one instance of each crate version across the entire workspace
• Prevents name clashes: Rust compiler sees consistent crate definitions
• Simplifies dependency management: Single source of truth for all crate versions
• Reduces build times: No duplicate compilation of the same crates
• Ensures consistency: All modules use identical crate versions and features

score-crates/
├── BUILD                   # Auto-generated aliases from @crate_index
├── MODULE.bazel            # Bazel module with crate specifications  
├── update_BUILD_file.sh    # Script to sync BUILD with @crate_index
└── README.md               # This file

The single source of truth for crate definitions using crate.spec():

module(name = "score-crates")

bazel_dep(name = "rules_rust", version = "0.61.0")

crate = use_extension("@rules_rust//crate_universe:extensions.bzl", "crate")

crate.spec(
    package = "clap",
    version = "4.5.4",
    features = ["derive"],
)
crate.spec(
    package = "futures", 
    version = "0.3.31",
)
# Add more crate.spec() calls here...

crate.from_specs(name = "crate_index")
use_repo(crate, "crate_index")

Contains auto-generated aliases pointing to @crate_index targets:

alias(
    name = "clap",
    actual = "@crate_index//:clap",
    visibility = ["//visibility:public"],
)

The update_BUILD_file.sh script automatically generates aliases for all crates found in @crate_index.

1. Add as a dependency in your MODULE.bazel:

bazel_dep(name = "score-crates", version = "1.0.0")

2. Use crates in your BUILD files:

load("@rules_rust//rust:defs.bzl", "rust_binary")

rust_binary(
    name = "my_app",
    srcs = ["main.rs"],
    deps = [
        "@score-crates//:clap",      # Via local aliases
        "@score-crates//:futures",   # Via local aliases
    ],
)

1. Edit MODULE.bazel - Add a new crate.spec() call:

crate.spec(
    package = "tokio",
    version = "1.40.0",
    features = ["full"],
)

1. Update aliases - Run the sync script:

./update_BUILD_file.sh

1. The crate will be available as:
   • @score-crates//:tokio (via local alias)