This page documents new features and bugfixes for cargo-nextest. Please see the stability policy for how versioning works with cargo-nextest.

0.9.38 - 2022-10-05


  • Test retries now support fixed delays and exponential backoffs, with optional jitter. See Delays and backoff for more information. Thanks Tomas Olvecky for your first contribution!

Internal improvements

  • Reading test data from standard output and standard error no longer buffers twice, just once. Thanks Jiahao XU for your first contribution!

Note to distributors: now that Rust 1.64 is out, process_group_bootstrap_hack is no longer supported or required. Please remove the following environment variables if you've set them:

  • RUSTFLAGS='--cfg process_group --cfg process_group_bootstrap_hack'

0.9.37 - 2022-09-30


  • Support for a negative value for --test-threads/-j, matching support in recent versions of Cargo. A value of -1 means the number of logical CPUs minus 1, and so on. Thanks Onigbinde Oluwamuyiwa Elijah for your first contribution!
  • Add a note to the help text for --test-threads indicating that its default value is obtained from the profile. Thanks jiangying for your first contribution!


  • Internal dependency target-spec bumped to 1.2.0 -- this means that newer versions of the windows crate are now supported.
  • MSRV updated to Rust 1.62.

0.9.36 - 2022-09-07


  • A new --hide-progress-bar option (environment variable NEXTEST_HIDE_PROGRESS_BAR) forces the progress bar to be hidden. Thanks Remo Senekowitsch for your first contribution!


  • Nextest now prints out a list of failing and flaky tests at the end of output by default (the final-status-level config is set to flaky).
  • The progress bar is now hidden if a CI environment is detected.

0.9.35 - 2022-08-17


  • Support for the --config argument, stabilized in Rust 1.63. This option is used to configure Cargo, not nextest. This argument is passed through to Cargo, and is also used by nextest to determine e.g. the target runner for a platform.

    --config is also how Miri communicates with nextest.

  • Target runners for cross-compilation now work with build archives. Thanks Pascal Kuthe for your first contribution!

0.9.34 - 2022-08-12


  • For cargo nextest self update, added -f as a short-form alias for --force.


  • Tests are no longer retried after a run is canceled. Thanks iskyzh for your contribution!

0.9.33 - 2022-07-31


  • Fixed regression in cargo-nextest 0.9.32 where it no longer produced any output if stderr wasn't a terminal.

0.9.32 - 2022-07-30


  • cargo nextest run now has a new --no-run feature to build but not run tests. (This was previously achievable with cargo nextest list -E 'none()', but is more intuitive this way.)
  • Pre-built binaries are now available for i686 Windows. Thanks Guiguiprim!

Internal improvements

  • Filter expression evaluation now uses a stack machine via the recursion crate. Thanks Inanna for your first contribution!

0.9.31 - 2022-07-27


  • Nextest sets a new NEXTEST_RUN_ID environment variable with a UUID for a test run. All tests run within a single invocation of cargo nextest run will set the same run ID. Thanks mitsuhiko for your first contribution!

0.9.30 - 2022-07-25


  • Fixed target runners specified as relative paths.

  • On Unix, cargo-nextest's performance had regressed (by 3x on clap) due to the change introduced in version 0.9.29 to put each test process into its own process group. In this version, this regression has been fixed, but only if you're using the pre-built binaries or building on Rust 1.64+ (currently in nightly).

    Note to distributors: to fix this regression while building with stable Rust 1.62, set the following environment variables:

    • RUSTFLAGS='--cfg process_group --cfg process_group_bootstrap_hack'

    This is temporary until the process_set_process_group feature is stabilized in Rust 1.64.

0.9.29 - 2022-07-24


  • On Unix, each test process is now put into its own process group. If a test times out or Ctrl-C is pressed, the entire process group is signaled. This means that most subprocesses spawned by tests are also killed.

    However, because process groups aren't nested, if a test creates a process group itself, those groups won't be signaled. This is a relatively uncommon situation.

  • On Windows, each test process is now associated with a job object. On timeouts, the entire job object is terminated. Since job objects are nested in recent versions of Windows, this should result in all subprocesses spawned by tests being killed.

    (On Windows, the Ctrl-C behavior hasn't changed. Nextest also doesn't do graceful shutdowns on Windows yet, though this may change in the future.)

  • Nextest can now parse Cargo configs specified via the unstable --config option.

  • Nextest now publishes binaries for aarch64-unknown-linux-gnu (#398) and x86_64-unknown-linux-musl (#399). Thanks messense and Teymour for your first contributions!


  • Per-test overrides are now additive across configuration files (including tool-specific configuration files).

0.9.29-rc.1 - 2022-07-24

This is a test release to ensure that releasing Linux aarch64 and musl binaries works well.

0.9.28 - 2022-07-22

This is a quick hotfix release to ensure that the right tokio features are enabled under default-no-update.

0.9.27 - 2022-07-22

This is a major architectural rework of nextest. We've tested it thoroughly to the best of our ability, but if you see regressions please report them!

If you encounter a regression, you can temporarily pin nextest to the previous version in CI. If you're on GitHub Actions and are using taiki-e/install-action, use this instead:

- uses: taiki-e/install-action@v1
- with:
    tool: nextest
    version: 0.9.26


  • Nextest now works with the Miri interpreter. Use cargo miri nextest run to run your tests with Miri.
  • Nextest now detects some situations where tests leak subprocesses. Previously, these situations would cause nextest to hang.
  • Per-test overrides now support slow-timeout and the new leak-timeout config parameter.
  • A new option --tool-config-file allows tools that wrap nextest to specify custom config settings, while still prioritizing repository-specific configuration.


  • Major internal change: The nextest list and run steps now use Tokio. This change enables the leak detection described above.
  • The list step now runs list commands in parallel. This should result in speedups in most cases.


  • Nextest now redirects standard input during test runs to /dev/null (or NUL on Windows). Most tests do not read from standard input, but if a test does, it will no longer cause nextest to hang.
  • On Windows, nextest configures standard input, standard output and standard error to not be inherited. This prevents some kinds of test hangs on Windows.
  • If a dynamic library link path doesn't exist, nextest no longer adds it to LD_LIBRARY_PATH or equivalent. This should have no practical effect.
  • Archiving tests now works even if the target directory is not called "target".

0.9.26 - 2022-07-14

This is a quick hotfix release to update the version of nextest-metadata, to which a breaking change was accidentally committed.

0.9.25 - 2022-07-13

This is a major release with several new features.

Filter expressions

Filter expressions are now ready for production. For example, to run all tests in nextest-runner and all its transitive dependencies within the workspace:

cargo nextest run -E 'deps(nextest-runner)'

This release includes a number of additions and changes to filter expressions.


  • The expression language supports several new predicates:
    • kind(name-matcher): include all tests in binary kinds (e.g. lib, test, bench) matching name-matcher.
    • binary(name-matcher): include all tests in binary names matching name-matcher.
    • platform(host) or platform(target): include all tests that are built for the host or target platform, respectively.


  • If a filter expression is guaranteed not to match a particular binary, it will not be listed by nextest. (This allows platform(host) and platform(target) to work correctly.)

  • If both filter expressions and standard substring filters are passed in, a test must match filter expressions AND substring filters to be executed. For example:

cargo nextest run -E 'package(nextest-runner)' test_foo test_bar

This will execute only the tests in nextest-runner that match test_foo or test_bar.

Per-test overrides

Nextest now supports per-test overrides. These overrides let you customize settings for subsets of tests. For example, to retry tests that contain the substring test_e2e 3 times:

filter = "test(test_e2e)"
retries = 3

Currently, only retries are supported. In the future, more kinds of customization will be added.

Other changes

  • A new environment variable NEXTEST_RETRIES controls the number of retries tests are run with. In terms of precedence, this slots in between the command-line --retries option and per-test overrides for retries.
  • cargo nextest list now hides skipped tests and binaries by default. To print out skipped tests and binaries, use cargo nextest list --verbose.
  • The Machine-readable output for cargo nextest list now contains a new "status" key. By default, this is set to "listed", and for binaries that aren't run because they don't match expression filters this is set to "skipped".
  • The --platform-filter option is deprecated, though it will keep working for all versions within the nextest 0.9 series. Use -E 'platform(host)' or -E 'platform(target)' instead.
  • cargo nextest run -- --skip and --exact now suggest using a filter expression instead.

0.9.24 - 2022-07-01


  • New config option profile.<profile-name>.test-threads controls the number of tests run simultaneously. This option accepts either an integer with the number of threads, or the string "num-cpus" (default) for the number of logical CPUs. As usual, this option is overridden by --test-threads and NEXTEST_TEST_THREADS, in that order.
  • The command-line --test-threads option and the NEXTEST_TEST_THREADS environment variable now accept num-cpus as their argument.
  • nextest now works with cargo binstall (#332). Thanks [Remoun] for your first contribution!


  • Within JUnit XML, test failure descriptions (text nodes for <failure> and <error> tags) now have invalid ANSI escape codes stripped from their output.

0.9.23 - 2022-06-26


  • On Windows, nextest now detects tests that abort due to e.g. an access violation (segfault) and prints their status as "ABORT" rather than "FAIL", along with an explanatory message on the next line.
  • Improved JUnit support: nextest now heuristically detects stack traces and adds them to the text node of the <failure> element (#311).


  • Errors that happen while writing data to the output now have a new documented exit code: WRITE_OUTPUT_ERROR.

0.9.22 - 2022-06-21


  • Benchmarks are now treated as normal tests. (#283, thanks @tabokie for your contribution!).

    Note that benchmarks are currently incompatible with nextest (#96) -- this change doesn't have any effect on that.

  • Added -F as a shortcut for --features, mirroring an upcoming addition to Cargo 1.62 (#287, thanks Alexendoo for your first contribution!)


  • If nextest's output is colorized, it no longer strips ANSI escape codes from test runs.

0.9.21 - 2022-06-17


  • On Unix, tests that fail due to a signal (e.g. SIGSEGV) will print out the name of the signal rather than the generic "FAIL".
  • cargo-nextest has a new "default-no-update" feature that will contain all default features except for self-update. If you're distributing nextest or installing it in CI, the recommended, forward-compatible way to build cargo-nextest is with --no-default-features --features default-no-update.


  • Progress bars now take up the entire width of the screen. This prevents issues with the bar wrapping around on terminals that aren't wide enough.

0.9.20 - 2022-06-13


  • Account for skipped tests when determining the length of the progress bar.

0.9.19 - 2022-06-13


  • Nextest can now update itself! Once this version is installed, simply run cargo nextest self update to update to the latest version.

    Note to distributors: you can disable self-update by building cargo-nextest with --no-default-features.

  • Partial, emulated support for test binary arguments passed in after cargo nextest run -- (#265, thanks @tabokie for your contribution!).

    For example, cargo nextest run -- my_test --ignored will run ignored tests containing my_test, similar to cargo test -- my_test --ignored.

    Support is limited to test names, --ignored and --include-ignored.

    Note to integrators: to reliably disable all argument parsing, pass in -- twice. For example, cargo nextest run -- -- <filters...>.


  • Better detection for cross-compilation -- now look through the CARGO_BUILD_TARGET environment variable, and Cargo configuration as well. The --target option is still preferred.
  • Slow and flaky tests are now printed out properly in the final status output (#270).

This is a test release.

0.9.18 - 2022-06-08


  • Support for terminating tests if they take too long, via the configuration parameter slow-timeout.terminate-after. For example, to time out after 120 seconds:

    slow-timeout = { period = "60s", terminate-after = 2 }

    Thanks steveeJ for your contribution (#214)!


  • Improved support for reusing builds: produce better error messages if the workspace's source is missing.

0.9.17 - 2022-06-07

This release contains a number of user experience improvements.


  • If producing output to an interactive terminal, nextest now prints out its status as a progress bar. This makes it easy to see the status of a test run at a glance.
  • Nextest's configuration has a new final-status-level option which can be used to print out some statuses at the end of a run (defaults to none). On the command line, this can be overridden with the --final-status-level argument or NEXTEST_FINAL_STATUS_LEVEL in the environment.
  • If a target runner is in use, nextest now prints out its name and the environment variable or config file the definition was obtained from.


  • If the creation of a test list fails, nextest now prints a more descriptive error message, and exits with the exit code 104 (TEST_LIST_CREATION_FAILED).

0.9.16 - 2022-06-02



  • While archiving build artifacts, work around some libraries producing linked paths that don't exist (#247). Print a warning for those paths instead of failing.


  • Build artifact archives no longer recurse into linked path subdirectories. This is not a behavioral change because LD_LIBRARY_PATH and other similar variables do not recurse into subdirectories either.

0.9.15 - 2022-05-31


  • Improved support for reusing builds:
    • New command cargo nextest archive automatically archives test binaries and other relevant files after building tests. Currently the .tar.zst format is supported.
    • New option cargo nextest run --archive-file automatically extracts archives before running the tests within them.
    • New runtime environment variable NEXTEST_BIN_EXE_<name> is set to the absolute path to a binary target's executable, taking path remapping into account. This is equivalent to CARGO_BIN_EXE_<name>, except this is set at runtime.
    • cargo nextest list --list-type binaries-only now records information about non-test binaries as well.


Fix for experimental feature filter expressions:

  • Fix test filtering when expression filters are set but name-based filters aren't.

0.9.14 - 2022-04-18


Fixes related to path remapping:

  • Directories passed into --workspace-remap and --target-dir-remap are now canonicalized.
  • If the workspace directory is remapped, CARGO_MANIFEST_DIR in tests' runtime environment is set to the new directory.

0.9.13 - 2022-04-16


  • Support for reusing builds is now production-ready. Build on one machine and run tests on another, including cross-compiling and test partitioning.

    To see how builds can be reused in GitHub Actions, see this example.

  • Experimental support for filter expressions, allowing fine-grained specifications for which tests to run.

Thanks to Guiguiprim for their fantastic work implementing both of these.

0.9.12 - 2022-03-22



  • Test binaries that link to dynamic libraries built by Cargo now work correctly (#82).
  • Crates with no tests are now skipped while computing padding widths in the reporter (#125).


  • MSRV updated to Rust 1.56.
  • For experimental feature reusing builds:
    • Change --binaries-dir-remap to --target-dir-remap and expect that the entire target directory is archived.
    • Support linking to dynamic libraries (#82).

0.9.11 - 2022-03-09


0.9.10 - 2022-03-07

Thanks to Guiguiprim for their contributions to this release!


  • A new --platform-filter option filters tests by the platform they run on (target or host).
  • cargo nextest list has a new --list-type option, with values full (the default, same as today) and binaries-only (list out binaries without querying them for the tests they contain).
  • Nextest executions done as a separate process per test (currently the only supported method, though this might change in the future) set the environment variable NEXTEST_PROCESS_MODE=process-per-test.

New experimental features

  • Nextest can now reuse builds across invocations and machines. This is an experimental feature, and feedback is welcome in #98!


  • The target runner is now build-platform-specific; test binaries built for the host platform will be run by the target runner variable defined for the host, and similarly for the target platform.

0.9.9 - 2022-03-03


  • Updates for Rust 1.59:
    • Support abbreviating --release as -r (Cargo #10133).
    • Stabilize future-incompat-report (Cargo #10165).
    • Update builtin list of targets (used by the target runner) to Rust 1.59.

0.9.8 - 2022-02-23


  • Target runners of the form runner = ["bin-name", "--arg1", ...] are now parsed correctly (#75).
  • Binary IDs for [[bin]] and [[example]] tests are now unique, in the format <crate-name>::bin/<binary-name> and <crate-name>::test/<binary-name> respectively (#76).

0.9.7 - 2022-02-23


  • If parsing target runner configuration fails, warn and proceed without a target runner rather than erroring out.

Known issues

  • Parsing an array of strings for the target runner currently fails: #73. A fix is being worked on in #75.

0.9.6 - 2022-02-22


0.9.5 - 2022-02-20


  • Updated nextest-runner to 0.1.2, fixing cyan coloring of module paths (#52).

0.9.4 - 2022-02-16

The big new change is that release binaries are now available! Head over to Pre-built binaries for more.


  • In test output, module paths are now colored cyan (#42).


  • While querying binaries to list tests, lines ending with ": benchmark" will now be ignored (#46).

0.9.3 - 2022-02-14


  • Add a BufWriter around stderr for the reporter, reducing the number of syscalls and fixing issues around output overlap on Windows (#35). Thanks @fdncred for reporting this!

0.9.2 - 2022-02-14


  • Running cargo nextest from within a crate now runs tests for just that crate, similar to cargo test. Thanks Yaron Wittenstein for reporting this!

0.9.1 - 2022-02-14


  • Updated nextest-runner to 0.1.1, fixing builds on Rust 1.54.

0.9.0 - 2022-02-14

Initial release. Happy Valentine's day!


Supported in this initial release: