Provided by: cargo_0.42.0-0ubuntu1_amd64 bug

NAME

       cargo-bench - Execute benchmarks of a package

SYNOPSIS

       cargo bench [OPTIONS] [BENCHNAME] [-- BENCH-OPTIONS]

DESCRIPTION

       Compile and execute benchmarks.

       The benchmark filtering argument BENCHNAME and all the arguments following the two dashes
       (--) are passed to the benchmark binaries and thus to libtest (rustc’s built in unit-test
       and micro-benchmarking framework). If you’re passing arguments to both Cargo and the
       binary, the ones after -- go to the binary, the ones before go to Cargo. For details about
       libtest’s arguments see the output of cargo bench  --help. As an example, this will run
       only the benchmark named foo (and skip other similarly named benchmarks like foobar):

           cargo bench -- foo --exact

       Benchmarks are built with the --test option to rustc which creates an executable with a
       main function that automatically runs all functions annotated with the #[bench] attribute.
       Cargo passes the --bench flag to the test harness to tell it to run only benchmarks.

       The libtest harness may be disabled by setting harness = false in the target manifest
       settings, in which case your code will need to provide its own main function to handle
       running benchmarks.

OPTIONS

   Benchmark Options
       --no-run
           Compile, but don’t run benchmarks.

       --no-fail-fast
           Run all benchmarks regardless of failure. Without this flag, Cargo will exit after the
           first executable fails. The Rust test harness will run all benchmarks within the
           executable to completion, this flag only applies to the executable as a whole.

   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...
           Benchmark only the specified packages. See cargo-pkgid(1) for the SPEC format. This
           flag may be specified multiple times.

       --workspace
           Benchmark 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 bench will build the following targets
       of the selected packages:

       ·   lib — used to link with binaries and benchmarks

       ·   bins (only if benchmark targets are built and required features are available)

       ·   lib as a benchmark

       ·   bins as benchmarks

       ·   benchmark targets

       The default behavior can be changed by setting the bench flag for the target in the
       manifest settings. Setting examples to bench = true will build and run the example as a
       benchmark. Setting targets to bench = false will stop them from being benchmarked by
       default. Target selection options that take a target by name ignore the bench flag and
       will always benchmark the given target.

       Passing target selection flags will benchmark only the specified targets.

       --lib
           Benchmark the package’s library.

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

       --bins
           Benchmark all binary targets.

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

       --examples
           Benchmark all example targets.

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

       --tests
           Benchmark 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...
           Benchmark the specified benchmark. This flag may be specified multiple times.

       --benches
           Benchmark 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
           Benchmark all targets. This is equivalent to specifying --lib --bins --tests --benches
           --examples.

   Feature Selection
       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.

       --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
           Benchmark 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>.

   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
       By default the Rust test harness hides output from benchmark execution to keep results
       readable. Benchmark output can be recovered (e.g., for debugging) by passing --nocapture
       to the benchmark binaries:

           cargo bench -- --nocapture

       -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
       -h, --help
           Prints help information.

       -Z FLAG...
           Unstable (nightly-only) flags to Cargo. Run cargo -Z help for details.

   Miscellaneous Options
       The --jobs argument affects the building of the benchmark executable but does not affect
       how many threads are used when running the benchmarks. The Rust test harness runs
       benchmarks serially in a single thread.

       -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.

       Benchmarks are always built with the bench profile. Binary and lib targets are built
       separately as benchmarks with the bench profile. Library targets are built with the
       release profiles when linked to binaries and benchmarks. Dependencies use the release
       profile.

       If you need a debug build of a benchmark, try building it with cargo-build(1) which will
       use the test profile which is by default unoptimized and includes debug information. You
       can then run the debug-enabled benchmark manually.

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. Build and execute all the benchmarks of the current package:

               cargo bench

        2. Run only a specific benchmark within a specific benchmark target:

               cargo bench --bench bench_name -- modname::some_benchmark

SEE ALSO

       cargo(1), cargo-test(1)

                                            2019-11-15                             CARGO-BENCH(1)