cargo fix

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!The cargo fix subcommand is also being developed for the Rust 2018 editionto provide code the ability to easily opt-in to the new edition without havingto worry about any breakage.

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 prepare for the 2018 edition, you can do so byexecuting:

  1. cargo fix --edition

which behaves the same as cargo check —all-targets. Similarly if you’d liketo fix code for different platforms you can do:

  1. cargo fix --edition --target x86_64-pc-windows-gnu

or if your crate has optional features:

  1. cargo fix --edition --no-default-features --features foo

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

OPTIONS

Fix options

  • —broken-code

  • Fix code even if it already has compiler errors. This is useful if cargofix fails to apply the changes. It will apply the changes and leave thebroken code in the working directory for you to inspect and manually fix.

  • —edition

  • Apply changes that will update the code to the latest edition. This willnot update the edition in the Cargo.toml manifest, which must be updatedmanually.

  • —edition-idioms

  • Apply suggestions that will update code to the preferred style for thecurrent edition.

  • —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.

  • -pSPEC…​
  • —packageSPEC…​

  • Fix only the specified packages. See cargo-pkgid(1) for theSPEC format. This flag may be specified multiple times.

  • —workspace

  • Fix all members in the workspace.

  • —all

  • Deprecated alias for —workspace.

  • —excludeSPEC…​

  • Exclude the specified packages. Must be used in conjunction with the—workspace flag. This flag may be specified multiple times.

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 thespecified targets.

  • —lib

  • Fix the package’s library.

  • —binNAME…​

  • Fix the specified binary. This flag may be specified multiple times.

  • —bins

  • Fix all binary targets.

  • —exampleNAME…​

  • Fix the specified example. This flag may be specified multiple times.

  • —examples

  • Fix all example targets.

  • —testNAME…​

  • Fix the specified integration test. This flag may be specified multipletimes.

  • —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.

  • —benchNAME…​

  • Fix the specified benchmark. This flag may be specified multiple times.

  • —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

When no feature options are given, the default feature is activated forevery selected package.

  • —featuresFEATURES

  • Space or comma separated list of features to activate. These features onlyapply to the current directory’s package. Features of direct dependenciesmay be enabled with <dep-name>/<feature-name> syntax.

  • —all-features

  • Activate all available features of all selected packages.

  • —no-default-features

  • Do not activate the default feature of the current directory’spackage.

Compilation Options

  • —targetTRIPLE
  • 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.

  • —release

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

  • —profileNAME

  • Changes fix behavior. Currently only test issupported, which will fix with the#[cfg(test)] attribute enabled. This is useful to have itfix unit tests which are usually excluded viathe cfg attribute. This does not change the actual profile used.

Output Options

  • —target-dirDIRECTORY
  • Directory for all generated artifacts and intermediate files. May also bespecified with the CARGO_TARGET_DIR environment variable, or thebuild.target-dir config value. Defaultsto 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.

  • -q

  • —quiet

  • No output printed to stdout.

  • —colorWHEN

  • 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.

  • —message-formatFMT
  • 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.

  • short: Emit shorter, human-readable text messages.

  • json: Emit JSON messages to stdout.

  • json-diagnostic-short: Ensure the rendered field of JSON messages containsthe "short" rendering from rustc.

  • json-diagnostic-rendered-ansi: Ensure the rendered field of JSON messagescontains embedded ANSI color codes for respecting rustc’s default colorscheme.

  • 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.

Manifest Options

  • —manifest-pathPATH

  • Path to the Cargo.toml file. By default, Cargo searches in the currentdirectory or any parent directory for the Cargo.toml file.

  • —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.

Common Options

  • -h
  • —help

  • Prints help information.

  • -ZFLAG…​

  • Unstable (nightly-only) flags to Cargo. Run cargo -Z help fordetails.

Miscellaneous Options

  • -jN
  • —jobsN
  • Number of parallel jobs to run. May also be specified with thebuild.jobs config value. Defaults tothe number of CPUs.

PROFILES

Profiles may be used to configure compiler options such as optimization levelsand debug settings. Seethe referencefor more details.

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.

TargetDefault Profile—release Profile
lib, bin, exampledevrelease
test, bench, or any target in "test" or "bench" modetestbench

Dependencies use the dev/release profiles.

ENVIRONMENT

See the reference fordetails on environment variables that Cargo reads.

Exit Status

  • 0

  • Cargo succeeded.

  • 101

  • Cargo failed to complete.

EXAMPLES

  • Apply compiler suggestions to the local package:
  1. cargo fix
  • Convert a 2015 edition to 2018:
  1. cargo fix --edition
  • Apply suggested idioms for the current edition:
  1. cargo fix --edition-idioms

SEE ALSO

cargo(1), cargo-check(1)