Cargo Doc and Rustdoc Query Recipes

A practical reference of commands and shell workflows for querying local rustdoc outputs and remote docs.rs pages with zero hallucination.

1. Targeted Local Documentation Builds

Building documentation for the entire dependency tree can take minutes and consume gigabytes of disk space. Always target specific packages with --no-deps.

# Build docs for a single dependency without transitive dependencies:
cargo doc -p egui --no-deps

# Build docs for multiple specific crates:
cargo doc -p egui -p bevy_egui --no-deps

# Build docs with all feature flags enabled to reveal conditional APIs:
cargo doc -p serde --all-features --no-deps

# Build docs exclusively for workspace crates:
cargo doc --workspace --no-deps

2. Navigating Local HTML Documentation via CLI

Local docs are located in target/doc/<crate_name>/.

Finding the Master Item Index

Every crate contains an all.html file listing all public types, traits, functions, and macros:

# Locate all items in crate:
cat target/doc/egui/all.html | grep -o -E 'href="[^"]+"' | head -n 30

Inspecting Methods on a Struct or Trait

Inspect the generated struct file directly to view method signatures and doc comments:

# Search for public methods on struct Ui:
grep -in "pub fn " target/doc/egui/struct.Ui.html | head -n 25

# View methods including return types:
grep -A 2 -in "pub fn " target/doc/egui/struct.Ui.html | head -n 40

3. Remote Docs.rs Querying (Pre-dependency Research)

When evaluating a crate before adding it to Cargo.toml, query docs.rs directly using predictable URL patterns.

The all.html Catalog

Fetch and filter the complete index of items:

# Find all structs matching 'Context':
curl -sL "https://docs.rs/bevy_egui/latest/bevy_egui/all.html" | grep -i "EguiContext"

# Verify trait implementations on a type:
curl -sL "https://docs.rs/egui/latest/egui/all.html" | grep -i "Widget"

Direct Item URLs

• Structs: https://docs.rs/<crate>/latest/<crate>/struct.<Name>.html
• Traits: https://docs.rs/<crate>/latest/<crate>/trait.<Name>.html
• Enums: https://docs.rs/<crate>/latest/<crate>/enum.<Name>.html
• Functions: https://docs.rs/<crate>/latest/<crate>/fn.<name>.html
• Modules: https://docs.rs/<crate>/latest/<crate>/<module>/index.html

4. Compiler Diagnostic Feedback Loop (cargo check)

When uncertain about an exact method signature or renamed symbol, write an approximate implementation and execute cargo check:

cargo check 2>&1 | head -n 35

rustc diagnostics deliver precise corrections:

• Similar method names (help: there is a method with a similar name: '...').
• Trait requirements (help: the following trait must be implemented: '...').
• Required imports (help: consider importing this struct: 'use egui::...').

Last updated Oct 08, 2026