cargo-fix(1)

{{*set command="fix"}} {{set actionverb="Fix"}} {{~set multitarget=true}}

NAME

cargo-fix --- Automatically fix lint warnings reported by rustc

SYNOPSIS

cargo fix [options]

DESCRIPTION

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

Executing cargo fix will under the hood execute {{man "cargo-check" 1}}. Any warnings applicable to your crate will be automatically fixed (if possible) and all remaining warnings will be displayed when the check process is finished. For example 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 with cargo check. If code is conditionally enabled with optional features, you will 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 to pass --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 questions or 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 one edition to the next. The general procedure is:

1. Run cargo fix --edition. Consider also using the --all-features flag if your project has multiple features. You may also want to run cargo fix --edition multiple times with different --target flags if your project has platform-specific code gated by cfg attributes.
2. Modify Cargo.toml to set the edition field to the new edition.
3. Run your project tests to verify that everything still works. If new warnings are issued, you may want to consider running cargo fix again (without the --edition flag) to apply any suggestions given by the compiler.

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

OPTIONS

Fix options

{{#options}}

{{#option "--broken-code" }} Fix code even if it already has compiler errors. This is useful if cargo fix fails to apply the changes. It will apply the changes and leave the broken code in the working directory for you to inspect and manually fix. {{/option}}

{{#option "--edition" }} Apply changes that will update the code to the next edition. This will not update the edition in the Cargo.toml manifest, which must be updated manually after cargo fix --edition has finished. {{/option}}

{{#option "--edition-idioms" }} Apply suggestions that will update code to the preferred style for the current edition. {{/option}}

{{#option "--allow-no-vcs" }} Fix code even if a VCS was not detected. {{/option}}

{{#option "--allow-dirty" }} Fix code even if the working directory has changes (including staged changes). {{/option}}

{{#option "--allow-staged" }} Fix code even if the working directory has staged changes. {{/option}}

{{/options}}

{{> section-package-selection }}

Target Selection

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

{{> options-targets }}

{{> section-features }}

Compilation Options

{{#options}}

{{> options-target-triple }}

{{> options-release }}

{{> options-profile-legacy-check }}

{{> options-timings }}

{{/options}}

Output Options

{{#options}} {{> options-target-dir }} {{/options}}

Display Options

{{#options}} {{> options-display }}

{{> options-message-format }} {{/options}}

Manifest Options

{{#options}} {{> options-manifest-path }}

{{> options-ignore-rust-version }}

{{> options-locked }}

{{/options}}

{{> section-options-common }}

Miscellaneous Options

{{#options}} {{> options-jobs }} {{> options-keep-going }} {{/options}}

{{> section-environment }}

{{> section-exit-status }}

EXAMPLES

1. Apply compiler suggestions to the local package:

   Copy

   cargo fix
   

2. Update a package to prepare it for the next edition:

   Copy

   cargo fix --edition
   

3. Apply suggested idioms for the current edition:

   Copy

   cargo fix --edition-idioms
   

SEE ALSO

{{man "cargo" 1}}, {{man "cargo-check" 1}}