cargo-fix(1)

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 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:

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.
Modify Cargo.toml to set the edition field to the new edition.
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

Package Selection

By default, when no package selection options are given, the packages selected depend 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 then the workspaces default members are selected, otherwise only the package defined by the manifest will be selected.

The default members of a workspace can be set explicitly with the workspace.default-members key in the root manifest. If this is not set, a virtual workspace will include all workspace members (equivalent to passing --workspace), and a non-virtual workspace will include only the root crate itself.

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.

Passing target selection flags will fix only the specified targets.

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.

Feature Selection

The feature flags allow you to control which features are enabled. When no feature options are given, the default feature is activated for every selected package.

See the features documentation for more details.

Compilation Options

Output Options

Display Options

Manifest Options

Common Options

Miscellaneous Options

ENVIRONMENT

See the reference for details on environment variables that Cargo reads.

EXIT STATUS

0: Cargo succeeded.
101: Cargo failed to complete.

EXAMPLES

Apply compiler suggestions to the local package:
```
cargo fix
```
Update a package to prepare it for the next edition:
```
cargo fix --edition
```
Apply suggested idioms for the current edition:
```
cargo fix --edition-idioms
```