CARGO-HELP(1)

NAME
cargo-help — Get help for a Cargo command

SYNOPSIS
cargo help [subcommand]

DESCRIPTION
Prints a help message for the given command.

For commands with subcommands, separate the command levels with spaces. For example, cargo help report future-incompatibilities displays help for the cargo report future-incompatibilities command.

Spaces separate hierarchy levels only between a parent command and its subcommands. Dashes that are part of a command’s name, such as generate-lockfile, must always be preserved.

Multiple command levels can also be written as a single dash-joined word. For example, cargo help report-future-incompatibilities is equivalent to cargo help report future-incompatibilities.

OPTIONS

  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>.

-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>.

  Manifest Options

--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 that 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.

  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 <https://rust-lang.github.io/rustup/overrides.html> for more information about how toolchain overrides work.

--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 <https://doc.rust-lang.org/cargo/reference/config.html#command-line-overrides> for more information.

-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 <https://doc.rust-lang.org/book/appendix-07-nightly-rust.html> 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.

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

EXIT STATUS

    • 0: Cargo succeeded.

    • 101: Cargo failed to complete.

EXAMPLES

    1. Get help for a command:

        cargo help build

    2. Get help for a nested command:

        cargo help report future-incompatibilities

    3. The dash-joined form also works:

        cargo help report-future-incompatibilities

    4. Help is also available with the --help flag:

        cargo build --help

SEE ALSO
cargo(1)