rust-ecosystem

name	rust-ecosystem
description	| Use when this capability is needed.

Quick Navigation

• references/cargo_config.md
• references/clippy_lints.md

Rust Ecosystem

The essential crates, tools, and patterns for productive Rust development.

Crate Selection Guide

Serialization

Need	Crate
JSON / YAML / TOML (derive)	serde + format crate
JSON	serde_json
TOML	toml
YAML	serde_yaml
MessagePack (binary)	rmp-serde
Protocol Buffers	prost
Fast binary	bincode, bitcode

HTTP & Networking

Need	Crate
HTTP client (async)	reqwest
HTTP client (sync)	ureq
Web framework	axum, actix-web
Low-level HTTP	hyper
gRPC	tonic
WebSocket	tokio-tungstenite

Async

Need	Crate
Async runtime	tokio (full), smol (light)
Async traits	async-trait
Streams	futures, tokio-stream
Async utilities	futures-util

Databases

Need	Crate
PostgreSQL / MySQL / SQLite (async)	sqlx
ORM	diesel
Redis	redis
MongoDB	mongodb
SQLite (sync)	rusqlite

Error Handling

Need	Crate
Library errors	thiserror
Application errors	anyhow
Fancy error output	miette

CLI

Need	Crate
Argument parsing	clap (derive)
Progress bars	indicatif
Terminal color	colored, nu-ansi-term
TUI	ratatui + crossterm
Terminal detect	atty, is-terminal

Data & Algorithms

Need	Crate
Faster HashMap	rustc-hash, ahash
SmallVec	smallvec, tinyvec
Concurrent data structures	dashmap, crossbeam
UUID	uuid
Dates/times	chrono, time
Regular expressions	regex
Random numbers	rand

Observability

Need	Crate
Structured logging	tracing
Log facade	log
tracing subscriber	tracing-subscriber
OpenTelemetry	opentelemetry, tracing-opentelemetry

Cargo Workspaces

For multi-crate projects, use workspaces to share dependencies and build settings:

# workspace Cargo.toml
[workspace]
members = ["crates/core", "crates/api", "crates/cli", "crates/worker"]
resolver = "2"  # Use this

# Share dependency versions across workspace
[workspace.dependencies]
tokio = { version = "1", features = ["full"] }
serde = { version = "1", features = ["derive"] }
anyhow = "1"
tracing = "0.1"
sqlx = { version = "0.8", features = ["postgres", "runtime-tokio-rustls"] }

# crates/api/Cargo.toml
[dependencies]
# Inherit version from workspace
tokio.workspace = true
serde.workspace = true
# Override features if needed
serde = { workspace = true, features = ["derive", "rc"] }
# Crate-specific dep
axum = "0.8"

# Workspace lint configuration
[workspace.lints.rust]
unsafe_code = "forbid"

[workspace.lints.clippy]
all = { level = "warn", priority = -1 }
pedantic = { level = "warn", priority = -1 }
# Specific overrides
module_name_repetitions = "allow"

Feature Flags

[features]
default = ["std"]
std = []
async = ["dep:tokio", "dep:futures"]
full = ["async", "tls"]
tls = ["dep:rustls", "dep:tokio-rustls"]

[dependencies]
tokio = { version = "1", optional = true }
rustls = { version = "0.23", optional = true }
tokio-rustls = { version = "0.26", optional = true }

// Conditional compilation
#[cfg(feature = "async")]
pub async fn fetch(url: &str) -> Result<String, Error> {
    reqwest::get(url).await?.text().await.map_err(Into::into)
}

#[cfg(not(feature = "std"))]
extern crate alloc; // no_std with alloc

// cfg_if for cleaner feature branches
use cfg_if::cfg_if;
cfg_if! {
    if #[cfg(feature = "tls")] {
        use rustls::ClientConfig;
        fn make_connector() -> ClientConnector { ClientConnector::new() }
    } else {
        fn make_connector() -> PlainConnector { PlainConnector::new() }
    }
}

Cargo Profile Configuration

[profile.dev]
opt-level = 0      # No optimization (fast compile)
debug = true       # Debug symbols
overflow-checks = true

[profile.release]
opt-level = 3      # Full optimization
lto = true         # Link-time optimization (slower compile, smaller/faster binary)
codegen-units = 1  # Single codegen unit for best optimization
panic = "abort"    # Smaller binary (no unwinding)
strip = true       # Strip symbols (add strip = "debuginfo" to keep some)

# For profiling: release speed + debug symbols
[profile.profiling]
inherits = "release"
debug = true
strip = false

# For benchmarks
[profile.bench]
opt-level = 3
lto = true

Essential Cargo Plugins

# Security audit
cargo install cargo-audit
cargo audit

# Deny specific licenses/advisories
cargo install cargo-deny
cargo deny check

# Expand macros (debug derive, etc.)
cargo install cargo-expand
cargo expand -- src/models.rs

# Faster linking (dev builds)
# Linux: use lld or mold
# Cargo.toml or .cargo/config.toml:
# [target.x86_64-unknown-linux-gnu]
# linker = "clang"
# rustflags = ["-C", "link-arg=-fuse-ld=mold"]

# Unused dependencies
cargo install cargo-udeps
cargo +nightly udeps

# Outdated dependencies
cargo install cargo-outdated
cargo outdated

# Benchmark/test with coverage
cargo install cargo-llvm-cov
cargo llvm-cov --html

# Binary size analysis
cargo install cargo-bloat
cargo bloat --release

# Watch mode (recompile on save)
cargo install cargo-watch
cargo watch -x test

Build Scripts (build.rs)

// build.rs — runs before compilation
fn main() {
    // Rerun only if these change
    println!("cargo:rerun-if-changed=build.rs");
    println!("cargo:rerun-if-changed=proto/");
    println!("cargo:rerun-if-env-changed=MY_API_KEY");

    // Link a C library
    println!("cargo:rustc-link-lib=ssl");
    println!("cargo:rustc-link-search=/usr/lib");

    // Set a cfg flag
    if cfg!(target_os = "windows") {
        println!("cargo:rustc-cfg=windows_target");
    }

    // Generate code at build time
    let out_dir = std::env::var("OUT_DIR").unwrap();
    let dest = std::path::Path::new(&out_dir).join("generated.rs");
    std::fs::write(dest, "pub const BUILD_DATE: &str = \"2025-01-01\";").unwrap();
}

// main.rs: include generated code
include!(concat!(env!("OUT_DIR"), "/generated.rs"));

Proc Macros (Custom Derives)

# my-macros/Cargo.toml
[lib]
proc-macro = true

[dependencies]
syn = { version = "2", features = ["full"] }
quote = "1"
proc-macro2 = "1"

// my-macros/src/lib.rs
use proc_macro::TokenStream;
use quote::quote;
use syn::{parse_macro_input, DeriveInput};

#[proc_macro_derive(MyTrait)]
pub fn derive_my_trait(input: TokenStream) -> TokenStream {
    let input = parse_macro_input!(input as DeriveInput);
    let name = &input.ident;

    let expanded = quote! {
        impl MyTrait for #name {
            fn name(&self) -> &str {
                stringify!(#name)
            }
        }
    };

    TokenStream::from(expanded)
}

Publishing to crates.io

[package]
name = "my-crate"
version = "0.1.0"
edition = "2021"
authors = ["Your Name <[e-mail]>"]
description = "A short description"
license = "MIT OR Apache-2.0"  # Standard Rust dual license
repository = "https://github.com/you/my-crate"
homepage = "https://my-crate.rs"
documentation = "https://docs.rs/my-crate"
keywords = ["keyword1", "keyword2"]  # Max 5, searchable
categories = ["data-structures"]    # From allowed list
readme = "README.md"
exclude = ["tests/", "benches/", ".github/"]

cargo login                  # Authenticate
cargo package --list         # Preview what will be published
cargo publish --dry-run      # Dry run
cargo publish                # Publish

CI Configuration (GitHub Actions)

# .github/workflows/ci.yml
name: CI
on: [push, pull_request]

jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: dtolnay/rust-toolchain@stable
      - uses: Swatinem/rust-cache@v2  # Cache build artifacts
      - run: cargo test --all-features --workspace

  clippy:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: dtolnay/rust-toolchain@stable
        with:
          components: clippy
      - run: cargo clippy --all-targets --all-features -- -D warnings

  fmt:
    runs-on: ubuntu-latest
    steps:
      - uses: 
        
        
           
          

  
     
    
        
        
        
             

Anti-Patterns

# Bad: default features silently pull in async runtimes, TLS stacks, or native deps.
serde = "1"
reqwest = "0.12"

# Good: choose feature surface explicitly.
serde = { version = "1", features = ["derive"] }
reqwest = { version = "0.12", default-features = false, features = ["json", "rustls-tls"] }

# Bad: publish without checking packaged contents.
cargo publish

# Good: inspect and dry-run first.
cargo package --list
cargo publish --dry-run

Maintenance Checklist

• Pin MSRV in docs and CI if the crate promises one.
• Audit default features for transitive dependency and compile-time impact.
• Run cargo tree -d before adding crates that may duplicate versions.
• Run cargo publish --dry-run and inspect cargo package --list.
• Use workspace-level dependencies for shared versions.
• Keep clippy, fmt, test, audit, and docs checks in CI.

References

• lib.rs — crate discovery
• blessed.rs — curated crate recommendations
• Cargo reference
• The rustup book

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Source: adxptived/Rust-Skills — distributed by TomeVault.