CARGO-RUN(1)

📦 version 1.80.1, in ubuntu jammy, ubuntu noble

💖 CARGO-RUN 💖

okay bestie, welcome to the cargo-run manual page — General Commands Manual energy, but make it cute. Let's get into it. ✨

🌸 NAME 🌸

cargo-run — run the current package 🏃♀️💨

✨ SYNOPSIS ✨

cargo run [options] [-- args]

🦋 DESCRIPTION 🦋

So basically, this runs a binary or an example of the local package. That's the whole vibe. 💅

Everything after those two dashes (--) gets passed straight to the binary you're running. And listen, because this trips people up: if you're passing args to both Cargo and the binary, the ones after -- go to the binary, and the ones before go to Cargo. Two lanes, no confusion. 🛣️

Also, unlike cargo-test(1) and cargo-bench(1), cargo run sets the working directory of the binary it executes to the current working directory — literally same as if you'd run it in the shell yourself. no cap. 😌

🎀 OPTIONS 🎀

📦 Package Selection

By default, the package in the current working directory is the one that gets selected. But if you want a different package in a workspace, the -p flag is right there. main character energy tbh. 👑

  • -p spec, --package spec — the package to run. Peep cargo-pkgid(1) for the SPEC format, iykyk.

🎯 Target Selection

When you don't give any target selection options, cargo run will run the binary target. If there are multiple binary targets, you must pass a target flag to pick one. OR — plot twist — the default-run field can be specified in the [package] section of Cargo.toml to choose the name of the binary to run by default. ✨

  • --bin name — run the specified binary.
  • --example name — run the specified example.

🧚 Feature Selection

The feature flags let you control which features get enabled. When you give no feature options, 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 — a space or comma separated list of features to activate. Features of workspace members may be enabled with the package-name/feature-name syntax. This flag may be specified multiple times, which enables all specified features. obsessed. 🔥
  • --all-features — activate all available features of all selected packages.
  • --no-default-features — do not activate the default feature of the selected packages.

🔨 Compilation Options

  • --target triple — run for the given architecture. The default is the host architecture. The general format of the triple is <arch><sub>-<vendor>-<sys>-<abi>. Run rustc --print target-list for a list of supported targets.

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

Heads up bestie: 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/guide/build-cache.html
  • -r, --release — run optimized artifacts with the release profile. See also the --profile option for choosing a specific profile by name. ✨
  • --profile name — run 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. double it and give it to the next person fr fr.
  • -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.
  • --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.
  • --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.
Beware bestie: this may result in different dependency resolution than online mode. Cargo will restrict itself to crates that are downloaded locally, even if there might be a newer version as indicated in the local copy of the index. 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. two-for-one special. 🍓

💜 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
  • --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 information: https://doc.rust-lang.org/cargo/reference/config.html#command-line-overrides
  • -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.
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). 🧚
  • -h, --help — prints help information.
  • -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. 🚫
  • --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 run -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 run -j1 --keep-going would definitely run both builds, even if the one run first fails. periodt. 💅

🌍 ENVIRONMENT 🌍

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

to be continued bestie… ⭐

💖 EXIT STATUS 💖

okay so when cargo run dips out, it tells you how it went with a number. two possible moods, that's it:

  • 0 — Cargo succeeded. slay. everything went how it was supposed to go, no notes, we love to see it. ✨
  • 101 — Cargo failed to complete. yeah… it did not eat. something broke, the build didn't finish, the vibe check was failed. 😭
ngl, 101 is the number. like, if you see it, bestie, something went sideways. not 1, not 2, it's giving very specific. that's just cargo's thing, iykyk. 💅

🌸 EXAMPLES 🌸

here's the part where i hold your hand and we do it together, fr fr. two little rituals, both iconic, both yours now:

  1. Build the local package and run its main target (assuming only one binary). just… the default. the classic. the main character move:
cargo run

that's it, that's the whole thing. one binary, no drama, it builds and runs. 🫶

  1. Run an example with extra arguments. this is when you wanna poke at an example instead of your main binary, and you got stuff to pass along to it:
cargo run --example exname -- --exoption exarg1 exarg2

okay and the way this one works is lowkey the whole tea: --example exname says "hey, run the example called exname", and then that lone -- is the little gate — everything after it gets handed straight to your program instead of to cargo. so --exoption, exarg1, exarg2 all go to the example itself. 🎀 without that --, cargo would be like "girl what are these" and get confused. respect the --. periodt. 💀

🦋 SEE ALSO 🦋

your reading list, bestie — go be nosy:

and that's a wrap on this page!! 🌈 this was CARGO-RUN(1), coming to you from the cargo manual — footer said so, and who am i to argue with a footer. 💖 run your stuff, pass your args, respect the --, and remember: exit 0 is a kiss, exit 101 is a lesson. mwah. 🎀✨🦋

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