Ubuntu Manpage: cargo-fix - Automatically fix lint warnings reported by rustc

Provided by: cargo_0.47.0-1~exp1ubuntu1~16.04.1_amd64

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! 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

OPTIONS

Fix options
--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.

--edition
Apply changes that will update the code to the latest edition. This will not update the edition in
the Cargo.toml manifest, which must be updated manually.

--edition-idioms
Apply suggestions that will update code to the preferred style for the current 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 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...
Fix only the specified packages. See cargo-pkgid(1) for the SPEC format. This flag may be specified
multiple times.

--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.

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.

--lib
Fix the package’s library.

--bin NAME...
Fix the specified binary. This flag may be specified multiple times.

--bins
Fix all binary targets.

--example NAME...
Fix the specified example. This flag may be specified multiple times.

--examples
Fix all example targets.

--test NAME...
Fix the specified integration test. This flag may be specified multiple times.

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

--bench NAME...
Fix the specified benchmark. This flag may be specified multiple times.

--benches
Fix all targets in benchmark mode that have the bench = true manifest flag set. By default this
includes the library and binaries built as benchmarks, and bench targets. Be aware that this will
also build any required dependencies, so the lib target may be built twice (once as a benchmark, and
once as a dependency for binaries, benchmarks, etc.). Targets may be enabled or disabled by setting
the bench flag in the manifest 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 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.

--features FEATURES
Space or comma separated list of features to activate. These features only apply to the current
directory’s package. Features of direct dependencies may be enabled with <dep-name>/<feature-name>
syntax. This flag may be 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 current directory’s package.

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

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.

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

--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 usually excluded via the cfg
attribute. This does not change the actual profile used.

Output Options
--target-dir DIRECTORY
Directory for all generated artifacts and intermediate files. May also be specified with the
CARGO_TARGET_DIR environment variable, or the build.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 which includes extra output such
as dependency warnings and build script output. May also be specified with the term.verbose config
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 the terminal.

• always: Always display colors.

• never: Never display colors.

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

--message-format FMT
The output format for diagnostic messages. Can be specified multiple times and 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. See the reference
<https://doc.rust-lang.org/cargo/reference/external-tools.html#json-messages> for more details.

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

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

• json-render-diagnostics: Instruct Cargo to not include rustc diagnostics in in JSON messages
printed, but instead Cargo itself should render the JSON diagnostics coming from rustc. Cargo’s
own JSON diagnostics and others coming from rustc are still emitted.

Manifest Options
--manifest-path PATH
Path to the Cargo.toml file. By default, Cargo searches for the Cargo.toml file in the current
directory or any parent directory.

--frozen, --locked
Either of these flags requires that the Cargo.lock file is up-to-date. If the lock file is missing,
or it needs to be updated, Cargo will exit with an error. The --frozen flag also prevents Cargo from
attempting to access the network to determine if it is out-of-date.

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.

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

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>.

Common Options
+TOOLCHAIN
If Cargo has been installed with rustup, and the first argument to cargo begins with +, it will be
interpreted as a rustup toolchain name (such as +stable or +nightly). See the rustup documentation
<https://github.com/rust-lang/rustup/> 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 the build.jobs config value
<https://doc.rust-lang.org/cargo/reference/config.html>. Defaults to the number of CPUs.

PROFILES

       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 │ test            │ bench             │
       │ in "test" or "bench" mode  │                 │                   │
       └────────────────────────────┴─────────────────┴───────────────────┘

       Dependencies use the dev/release profiles.

ENVIRONMENT

       See the reference <https://doc.rust-lang.org/cargo/reference/environment-variables.html> for details on
       environment variables that Cargo reads.

EXIT STATUS

       0
           Cargo succeeded.

       101
           Cargo failed to complete.

EXAMPLES

        1. Apply compiler suggestions to the local package:

               cargo fix

        2. Convert a 2015 edition to 2018:

               cargo fix --edition

        3. Apply suggested idioms for the current edition:

               cargo fix --edition-idioms