cargo-fix - Automatically fix lint warnings reported by rustc
cargo fix [OPTIONS]
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! The cargo fix subcommand is also being developed for the Rust 2018 edition to provide code the ability to easily opt-in to the new edition without having to worry about any breakage.
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 prepare for the 2018 edition, you can do so by executing:
cargo fix --edition
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 --edition --features foo
Similarly, other cfg expressions like platform-specific code will need to pass --target to fix code for the given target.
cargo fix --edition --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>
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.
-p SPEC..., --package SPEC...
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.
The feature flags allow you to control the enabled features for the "current" package. The "current" package is the package in the current directory, or the one specified in --manifest-path. If running in the root of a virtual workspace, then the default features are selected for all workspace members, or all features if --all-features is specified.
When no feature options are given, the default feature is activated for every selected package.
This may also be specified with the build.target config value <https://doc.rust-lang.org/cargo/reference/config.html>.
Note that specifying this flag makes Cargo run in a different mode where the target artifacts are placed in a separate directory. See the build cache <https://doc.rust-lang.org/cargo/guide/build-cache.html> documentation for more details.
May also be specified with the term.color config value <https://doc.rust-lang.org/cargo/reference/config.html>.
These may be used in environments where you want to assert that the Cargo.lock file is up-to-date (such as a CI build) or want to avoid network access.
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>.
-j N, --jobs N
Profiles may be used to configure compiler options such as optimization levels and debug settings. See the reference <https://doc.rust-lang.org/cargo/reference/profiles.html> for more details.
Profile selection depends on the target and crate being built. By default the dev or test profiles are used. If the --release flag is given, then the release 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.
See the reference <https://doc.rust-lang.org/cargo/reference/environment-variables.html> for details on environment variables that Cargo reads.
cargo fix --edition
cargo fix --edition-idioms