MAN page from OpenSuSE cargo-1.52.1-6.1.i586.rpm

CARGO\-FIX

Section: Misc. Reference Manual Pages (1)
Index

NAME

cargo-fix - Automatically fix lint warnings reported by rustc

SYNOPSIS

cargo fix [options]

DESCRIPTION

This Cargo subcommand will automatically take rustc's suggestions fromdiagnostics like warnings and apply them to your source code. This is intendedto help automate tasks that rustc itself already knows how to tell you to fix!

Executing cargo fix will under the hood execute cargo-check(1). Any warningsapplicable to your crate will be automatically fixed (if possible) and allremaining warnings will be displayed when the check process is finished. Forexample if you'd like to apply all fixes to the current package, you can run:

cargo fix

which behaves the same as cargo check --all-targets.

cargo fix is only capable of fixing code that is normally compiled withcargo check. If code is conditionally enabled with optional features, youwill need to enable those features for that code to be analyzed:

cargo fix --features foo

Similarly, other cfg expressions like platform-specific code will need topass --target to fix code for the given target.

cargo fix --target x86_64-pc-windows-gnu

If you encounter any problems with cargo fix or otherwise have any questionsor feature requests please don't hesitate to file an issue at<https://github.com/rust-lang/cargo>.

Edition migration

The cargo fix subcommand can also be used to migrate a package from oneedition <https://doc.rust-lang.org/edition-guide/editions/transitioning-an-existing-project-to-a-new-edition.html> to the next. The general procedure is:

: 1.Run cargo fix --edition. Consider also using the --all-features flag ifyour project has multiple features. You may also want to run cargo fix --edition multiple times with different --target flags if your projecthas platform-specific code gated by cfg attributes.

: 2.Modify Cargo.toml to set the edition field <https://doc.rust-lang.org/cargo/reference/manifest.html#the-edition-field> to the new edition.

: 3.Run your project tests to verify that everything still works. If newwarnings are issued, you may want to consider running cargo fix again(without the --edition flag) to apply any suggestions given by thecompiler.

And hopefully that's it! Just keep in mind of the caveats mentioned above thatcargo fix cannot update code for inactive features or cfg expressions.Also, in some rare cases the compiler is unable to automatically migrate allcode to the new edition, and this may require manual changes after buildingwith the new edition.

OPTIONS

Fix options

--broken-code

: Fix code even if it already has compiler errors. This is useful if cargo fixfails to apply the changes. It will apply the changes and leave the brokencode in the working directory for you to inspect and manually fix.

--edition

: Apply changes that will update the code to the next edition. This will notupdate the edition in the Cargo.toml manifest, which must be updatedmanually after cargo fix --edition has finished.

--edition-idioms

: Apply suggestions that will update code to the preferred style for the currentedition.

--allow-no-vcs

: Fix code even if a VCS was not detected.

--allow-dirty

: Fix code even if the working directory has changes.

--allow-staged

: Fix code even if the working directory has staged changes.

Package Selection

By default, when no package selection options are given, the packages selecteddepend 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 thenthe workspaces default members are selected, otherwise only the package definedby the manifest will be selected.

The default members of a workspace can be set explicitly with theworkspace.default-members key in the root manifest. If this is not set, avirtual 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...

: Fix only the specified packages. See cargo-pkgid(1) for theSPEC format. This flag may be specified multiple times and supports common Unixglob patterns like *, ? and []. However, to avoid your shell accidentally expanding glob patterns before Cargo handles them, you must use single quotes ordouble quotes around each pattern.

--workspace

: Fix all members in the workspace.

--all

: Deprecated alias for --workspace.

--exclude SPEC...

: Exclude the specified packages. Must be used in conjunction with the--workspace flag. This flag may be specified multiple times and supportscommon Unix glob patterns like *, ? and []. However, to avoid your shellaccidentally expanding glob patterns before Cargo handles them, you must usesingle quotes or double quotes around each pattern.

Target Selection

When no target selection options are given, cargo fix will fix all targets(--all-targets implied). Binaries are skipped if they haverequired-features that are missing.

Passing target selection flags will fix only the specifiedtargets.

Note that --bin, --example, --test and --bench flags also support 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 glob pattern.

--lib

: Fix the package's library.

--bin name...

: Fix the specified binary. This flag may be specified multiple timesand supports common Unix glob patterns.

--bins

: Fix all binary targets.

--example name...

: Fix the specified example. This flag may be specified multiple timesand supports common Unix glob patterns.

--examples

: Fix all example targets.

--test name...

: Fix the specified integration test. This flag may be specifiedmultiple times and supports common Unix glob patterns.

--tests

: Fix all targets in test mode that have the test = true manifestflag set. By default this includes the library and binaries built asunittests, and integration tests. Be aware that this will also build anyrequired dependencies, so the lib target may be built twice (once as aunittest, and once as a dependency for binaries, integration tests, etc.).Targets may be enabled or disabled by setting the test flag in themanifest settings for the target.

--bench name...

: Fix the specified benchmark. This flag may be specified multipletimes and supports common Unix glob patterns.

--benches

: Fix all targets in benchmark mode that have the bench = truemanifest flag set. By default this includes the library and binaries builtas benchmarks, and bench targets. Be aware that this will also build anyrequired dependencies, so the lib target may be built twice (once as abenchmark, and once as a dependency for binaries, benchmarks, etc.).Targets may be enabled or disabled by setting the bench flag in themanifest settings for the target.

--all-targets

: Fix all targets. This is equivalent to specifying --lib --bins --tests --benches --examples.

Feature Selection

The feature flags allow you to control which features are enabled. When nofeature options are given, the default feature is activated for everyselected package.

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

--features features

: Space or comma separated list of features to activate. Features of workspacemembers may be enabled with package-name/feature-name syntax. This flag maybe specified multiple times, which enables all specified features.

--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

Fix for the given architecture. The default is the hostarchitecture. The general format of the triple is<arch><sub>-<vendor>-<sys>-<abi>. Run rustc --print target-list for alist of supported targets.

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

Note that specifying this flag makes Cargo run in a different mode where thetarget artifacts are placed in a separate directory. See thebuild cache <https://doc.rust-lang.org/cargo/guide/build-cache.html> documentation for more details.

--release

: Fix optimized artifacts with the release profile. See thePROFILES section for details on how this affects profileselection.

--profile name

: Changes fix behavior. Currently only test is supported,which will fix with the #[cfg(test)] attribute enabled.This is useful to have it fix unit tests which are usuallyexcluded via the cfg attribute. This does not change the actual profileused.

Output Options

--target-dir directory

: Directory for all generated artifacts and intermediate files. May also bespecified with the CARGO_TARGET_DIR environment variable, or thebuild.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 whichincludes extra output such as dependency warnings and build script output.May also be specified with the term.verboseconfig value <https://doc.rust-lang.org/cargo/reference/config.html>.

-q, --quiet

: No output printed to stdout.

--color when

Control when colored output is used. Valid values:

: •auto (default): Automatically detect if color support is available on theterminal.

: •always: Always display colors.

: •never: Never display colors.

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

--message-format fmt

The output format for diagnostic messages. Can be specified multiple timesand consists of comma-separated values. Valid values:

: •human (default): Display in a human-readable text format. Conflicts withshort and json.

: •short: Emit shorter, human-readable text messages. Conflicts with humanand json.

: •json: Emit JSON messages to stdout. Seethe reference <https://doc.rust-lang.org/cargo/reference/external-tools.html#json-messages>for more details. Conflicts with human and short.

: •json-diagnostic-short: Ensure the rendered field of JSON messages containsthe "short" rendering from rustc. Cannot be used with human or short.

: •json-diagnostic-rendered-ansi: Ensure the rendered field of JSON messagescontains embedded ANSI color codes for respecting rustc's default colorscheme. Cannot be used with human or short.

: •json-render-diagnostics: Instruct Cargo to not include rustc diagnostics inin JSON messages printed, but instead Cargo itself should render theJSON diagnostics coming from rustc. Cargo's own JSON diagnostics and otherscoming 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 theCargo.toml file in the current directory or any parent directory.

--frozen, --locked

: Either of these flags requires that the Cargo.lock file isup-to-date. If the lock file is missing, or it needs to be updated, Cargo willexit with an error. The --frozen flag also prevents Cargo fromattempting to access the network to determine if it is out-of-date.
These may be used in environments where you want to assert that theCargo.lock file is up-to-date (such as a CI build) or want to avoid networkaccess.

--offline

Prevents Cargo from accessing the network for any reason. Without thisflag, Cargo will stop with an error if it needs to access the network andthe network is not available. With this flag, Cargo will attempt toproceed without the network if possible.

Beware that this may result in different dependency resolution than onlinemode. Cargo will restrict itself to crates that are downloaded locally, evenif 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 goingoffline.

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

Common Options

+toolchain

: If Cargo has been installed with rustup, and the first argument to cargobegins with +, it will be interpreted as a rustup toolchain name (suchas +stable or +nightly).See the rustup documentation <https://rust-lang.github.io/rustup/overrides.html>for more information about how toolchain overrides work.

-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 thebuild.jobs config value <https://doc.rust-lang.org/cargo/reference/config.html>. Defaults tothe number of CPUs.

PROFILES

Profiles may be used to configure compiler options such as optimization levelsand debug settings. See the reference <https://doc.rust-lang.org/cargo/reference/profiles.html> for moredetails.

Profile selection depends on the target and crate being built. By default thedev or test profiles are used. If the --release flag is given, then therelease or bench profiles are used.

Target Default Profile --release Profile
lib, bin, example dev release
test, bench, or any target in "test" or "bench" mode test bench

Dependencies use the dev/release profiles.