CARGO-DOC(1)

📦 version 1.93.1, in ubuntu resolute

💖 CARGO-DOC — the manual page, bestie edition 💖

okay so this is the cargo-doc manual, and no cap, it's actually so useful. it lives in the General Commands Manual section of your system, and it's all about building docs. let's get into it 🫶

✨ NAME ✨

cargo-doc — literally just: build a package's documentation. that's the whole vibe. 📚

🌸 SYNOPSIS 🌸

cargo doc [options]

that's it. that's the whole shape of it. cargo doc plus whatever flags you're feeling that day. 💅

🦋 DESCRIPTION 🦋

So here's the tea: cargo doc builds the documentation for your local package and all its dependencies. The output gets dropped into target/doc, in rustdoc's usual format. Iconic. ✨

Note, and this one's important: documentation generation is cumulative. That means existing doc files in the target directory are preserved across different cargo doc invocations. So if you run it, then change stuff, then run it again, the old stuff doesn't just vanish — it's still chilling there. If you actually want to remove existing generated docs, you gotta pass --doc to cargo-clean(1). That's the move. 🧹

👑 OPTIONS 👑

💜 Documentation Options

  • --open — Opens the docs in a browser after building them. It'll use your default browser, unless you define another one in the BROWSER environment variable, or use the doc.browser configuration option (link: https://doc.rust-lang.org/cargo/reference/config.html#docbrowser). pop off, browser of choice. 🌈
  • --no-deps — Does NOT build documentation for dependencies. Just your stuff. no extras. 🚫
  • --document-private-items — Includes non-public items in the documentation. And heads up: this gets enabled by default if you're documenting a binary target. so for binaries it's already on, bestie. 🔍

💖 Package Selection

okay so this section is giving "who even gets documented around here" energy. By default, when no package selection options are given, the packages selected depend on the selected manifest file (based on the current working directory, if --manifest-path is not given). If the manifest is the root of a workspace, then the workspace's default members are selected. Otherwise, only the package defined by the manifest gets selected. 🎀

The default members of a workspace can be set explicitly with the workspace.default-members key in the root manifest. If that's not set:

  • a virtual workspace will include all workspace members (equivalent to passing --workspace), and
  • a non-virtual workspace will include only the root crate itself.
  • -p *spec*…, --package *spec*… — Document only the specified packages. See cargo-pkgid(1) for the SPEC format. This flag may be specified multiple times and supports common Unix glob patterns like *, ? and []. BUT — and this is the part everyone messes up — to avoid your shell accidentally expanding glob patterns before Cargo handles them, you must use single quotes or double quotes around each pattern. quotes are not optional here, fr fr. 🙈
  • --workspace — Document all members in the workspace. everybody gets a doc. 🫶
  • --all — Deprecated alias for --workspace. it's old, it still works, but it's giving legacy. 💀
  • --exclude *SPEC*… — Exclude the specified packages. Must be used in conjunction with the --workspace flag — so it can't stand alone, okay? This flag may be specified multiple times and supports common Unix glob patterns like *, ? and []. However, to avoid your shell accidentally expanding glob patterns before Cargo handles them, you must use single quotes or double quotes around each pattern. same rule as before. 🌸

🎀 Target Selection

When no target selection options are given, cargo doc will document all binary and library targets of the selected package. The binary will be skipped if its name is the same as the lib target. Binaries are skipped if they have required-features that are missing. so yeah, sometimes things just don't make the cut. 😭

The default behavior can be changed by setting doc = false for the target in the manifest settings. And plot twist: using target selection options will ignore the doc flag and will always document the given target. so if you ask for it explicitly, you're getting it. periodt. 💅

  • --lib — Document the package's library. 📚
  • --bin *name*… — Document the specified binary. This flag may be specified multiple times and supports common Unix glob patterns. ⭐
  • --bins — Document all binary targets. all of them. 🔥
  • --example *name*… — Document the specified example. This flag may be specified multiple times and supports common Unix glob patterns. 🌈
  • --examples — Document all example targets. every single one. ✨

🧚 Feature Selection

The feature flags let you control which features are enabled. When no feature options are given, the default feature is activated for every selected package. 🎀

See the features documentation for more details: https://doc.rust-lang.org/cargo/reference/features.html#command-line-feature-options

  • -F features, --features features — Space or comma separated list of features to activate. Features of workspace members may be enabled with package-name/feature-name syntax. This flag may be specified multiple times, which enables all specified features. stack 'em up. 💅
  • --all-features — Activate all available features of all selected packages. everything, everywhere, all at once. 👑
  • --no-default-features — Do not activate the default feature of the selected packages. nope, skipping that one. 🚫

💅 Compilation Options

  • --target triple — Document for the specified target architecture. The flag may be specified multiple times. The default is the host architecture. The general format of the triple is <arch><sub>-<vendor>-<sys>-<abi>.

Possible values:

  • Any supported target in rustc --print target-list.
  • "host-tuple", which will internally be substituted by the host's target. This can be particularly useful if you're cross-compiling some crates, and don't want to specify your host's machine as a target (for instance, an xtask in a shared project that may be worked on by many hosts).
  • A path to a custom target specification. See Custom Target Lookup Path for more information: https://doc.rust-lang.org/rustc/targets/custom.html#custom-target-lookup-path

This may also be specified with the build.target config value: https://doc.rust-lang.org/cargo/reference/config.html

Heads up: specifying this flag makes Cargo run in a different mode where the target artifacts are placed in a separate directory. See the build cache documentation for more details: https://doc.rust-lang.org/cargo/reference/build-cache.html
  • -r, --release — Document optimized artifacts with the release profile. See also the --profile option for choosing a specific profile by name. 🔥
  • --profile name — Document with the given profile. See the reference for more details on profiles: https://doc.rust-lang.org/cargo/reference/profiles.html
  • --timings=fmts — Output information about how long each compilation takes, and track concurrency information over time. Accepts an optional comma-separated list of output formats; --timings without an argument will default to --timings=html. Specifying an output format (rather than the default) is unstable and requires -Zunstable-options. Valid output formats:
    • html (unstable, requires -Zunstable-options): Write a human-readable file cargo-timing.html to the target/cargo-timings directory with a report of the compilation. Also write a report to the same directory with a timestamp in the filename if you want to look at older runs. HTML output is suitable for human consumption only, and does not provide machine-readable timing data. 👀
    • json (unstable, requires -Zunstable-options): Emit machine-readable JSON information about timing information. 🤖

🌈 Output Options

  • --target-dir directory — Directory for all generated artifacts and intermediate files. May also be specified with the CARGO_TARGET_DIR environment variable, or the build.target-dir config value: https://doc.rust-lang.org/cargo/reference/config.html. Defaults to target in the root of the workspace. 📁

⭐ Display Options

  • -v, --verbose — Use verbose output. May be specified twice for "very verbose" output, which includes extra output such as dependency warnings and build script output. May also be specified with the term.verbose config value: https://doc.rust-lang.org/cargo/reference/config.html. the more v's, the more tea. 🍓
  • -q, --quiet — Do not print cargo log messages. May also be specified with the term.quiet config value: https://doc.rust-lang.org/cargo/reference/config.html. shhh. 🤫
  • --color when — Control when colored output is used. Valid values:
    • auto (default): Automatically detect if color support is available on the terminal.
    • always: Always display colors.
    • never: Never display colors.

May also be specified with the term.color config value: https://doc.rust-lang.org/cargo/reference/config.html. 🌈

  • --message-format fmt — The output format for diagnostic messages. Can be specified multiple times and consists of comma-separated values. Valid values:
    • human (default): Display in a human-readable text format. Conflicts with short and json.
    • short: Emit shorter, human-readable text messages. Conflicts with human and json.
    • json: Emit JSON messages to stdout. See the reference for more details: https://doc.rust-lang.org/cargo/reference/external-tools.html#json-messages. Conflicts with human and short.
    • json-diagnostic-short: Ensure the rendered field of JSON messages contains the "short" rendering from rustc. Cannot be used with human or short.
    • json-diagnostic-rendered-ansi: Ensure the rendered field of JSON messages contains embedded ANSI color codes for respecting rustc's default color scheme. Cannot be used with human or short.
    • json-render-diagnostics: Instruct Cargo to not include rustc diagnostics in JSON messages printed, but instead Cargo itself should render the JSON diagnostics coming from rustc. Cargo's own JSON diagnostics and others coming from rustc are still emitted. Cannot be used with human or short.

🦋 Manifest Options

  • --manifest-path path — Path to the Cargo.toml file. By default, Cargo searches for the Cargo.toml file in the current directory or any parent directory. 🔍
  • --ignore-rust-version — Ignore rust-version specification in packages. we're not checking that today. 🙈
  • --locked — Asserts that the exact same dependencies and versions are used as when the existing Cargo.lock file was originally generated. Cargo will exit with an error when either of the following scenarios arises:
    • The lock file is missing.
    • Cargo attempted to change the lock file due to a different dependency resolution.

It may be used in environments where deterministic builds are desired, such as in CI pipelines. 🔒

  • --offline — Prevents Cargo from accessing the network for any reason. Without this flag, Cargo will stop with an error if it needs to access the network and the network is not available. With this flag, Cargo will attempt to proceed without the network if possible. airplane mode but for cargo. ✈️

(part 1 done — more coming, don't go anywhere bestie 💖)

...and this is where it gets real: beware bestie, because going offline can legitimately give you different dependency resolution than online mode does. Cargo will restrict itself to crates that are already downloaded locally, even if there might be a newer version as indicated in the local copy of the index. So like, the vibes are local-only, no cap. Want to actually download stuff first? See the cargo-fetch(1) command to download dependencies before going offline. 🫶

May also be specified with the net.offline config value — https://doc.rust-lang.org/cargo/reference/config.html.

  • --frozen — Equivalent to specifying both --locked and --offline. That's it, that's the whole flag, two-for-one combo meal. 🍓
  • --lockfile-path PATH — Changes the path of the lockfile from the default (<workspace_root>/Cargo.lock) to PATH. PATH must end with Cargo.lock (e.g. --lockfile-path /tmp/temporary-lockfile/Cargo.lock). Note that providing --lockfile-path will ignore existing lockfile at the default path, and instead will either use the lockfile from PATH, or write a new lockfile into the provided PATH if it doesn't exist. This flag can be used to run most commands in read-only directories, writing lockfile into the provided PATH. Iconic behaviour honestly.
This option is only available on the nightly channel and requires the -Z unstable-options flag to enable (see #14421 — https://github.com/rust-lang/cargo/issues/14421). Nightly channel link: https://doc.rust-lang.org/book/appendix-07-nightly-rust.html. 💀

🌈 Common Options 🌈

  • +toolchain — If Cargo has been installed with rustup, and the first argument to cargo begins with +, it will be interpreted as a rustup toolchain name (such as +stable or +nightly). See the rustup documentation for more information about how toolchain overrides work — https://rust-lang.github.io/rustup/overrides.html. Yes bestie, a plus sign at the front is doing so much work here. 💅
  • --config KEY=VALUE or PATH — Overrides a Cargo configuration value. The argument should be in TOML syntax of KEY=VALUE, or provided as a path to an extra configuration file. This flag may be specified multiple times. See the command-line overrides section for more info — https://doc.rust-lang.org/cargo/reference/config.html#command-line-overrides. Stack it like bracelets. ✨
  • -C PATH — Changes the current working directory before executing any specified operations. This affects things like where cargo looks by default for the project manifest (Cargo.toml), as well as the directories searched for discovering .cargo/config.toml, for example. This option must appear before the command name, for example cargo -C path/to/my-project build. Not me putting the flag in the wrong spot and getting confused 😭 — before the command name, always.
This option is only available on the nightly channel and requires the -Z unstable-options flag to enable (see #10098 — https://github.com/rust-lang/cargo/issues/10098). Nightly channel link: https://doc.rust-lang.org/book/appendix-07-nightly-rust.html.
  • -h, --help — Prints help information. The original main character of every CLI, fr fr. 👑
  • -Z flag — Unstable (nightly-only) flags to Cargo. Run cargo -Z help for details.

🎀 Miscellaneous Options 🎀

  • -j N, --jobs N — Number of parallel jobs to run. May also be specified with the build.jobs config value (https://doc.rust-lang.org/cargo/reference/config.html). Defaults to the number of logical CPUs. If negative, it sets the maximum number of parallel jobs to the number of logical CPUs plus provided value. If a string default is provided, it sets the value back to defaults. Should not be 0. Like, don't. Zero jobs is giving nothing. 🍓
  • --keep-going — Build as many crates in the dependency graph as possible, rather than aborting the build on the first one that fails to build.

For example if the current package depends on dependencies fails and works, one of which fails to build, cargo doc -j1 may or may not build the one that succeeds (depending on which one of the two builds Cargo picked to run first), whereas cargo doc -j1 --keep-going would definitely run both builds, even if the one run first fails.

🌸 ENVIRONMENT 🌸

See the reference for details on environment variables that Cargo reads — https://doc.rust-lang.org/cargo/reference/environment-variables.html.

💖 EXIT STATUS 💖

  • 0: Cargo succeeded. 🎉
  • 101: Cargo failed to complete. 🫠

⭐ EXAMPLES ⭐

  1. Build the local package documentation and its dependencies and output to target/doc.
cargo doc

🦋 SEE ALSO 🦋

cargo(1), cargo-rustdoc(1), rustdoc(1)

And that's a wrap on cargo-doc(1), bestie — part of the Cargo manual, dated and shipped alongside the rest of the docs. Go build yourself some gorgeous docs, you absolute icon. 💖✨🎀

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