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! 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:
o auto (default): Automatically detect if color support is
available on the terminal.
o always: Always display colors.
o 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:
o human (default): Display in a human-readable text format.
o short: Emit shorter, human-readable text messages.
o json: Emit JSON messages to stdout. See the reference
<https://doc.rust-lang.org/cargo/reference/external-tools.html#json-messages>
for more details.
o json-diagnostic-short: Ensure the rendered field of JSON messages
contains the "short" rendering from rustc.
o json-diagnostic-rendered-ansi: Ensure the rendered field of JSON
messages contains embedded ANSI color codes for respecting
rustc's default color scheme.
o 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://rust-lang.github.io/rustup/overrides.html> 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 | --release |
| | Profile | Profile |
+----------------------------------------+-------------+--------------+
| lib, bin, example | dev | release |
+----------------------------------------+-------------+--------------+
| test, bench, or any target in "test" | test | bench |
| 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
o 0: Cargo succeeded.
o 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
SEE ALSO
cargo(1), cargo-check(1)