v24.9.0

24.9.0

• Fixed: Avoid generating empty string elements in ENCODED_RUSTFLAGS when --cap-lints is set. In some situations these could cause a compiler error complaining about the empty argument.

• New: --profile option allows selecting a Cargo profile. In particular, it's recommended that you can use --profile=mutants and configure a custom profile in your Cargo.toml to optimize the build for mutants, by turning off debug symbols.

• New: --iterate option skips mutants that were previously caught or unviable.

• New: cargo-mutants starts a GNU jobserver, shared across all children, so that running multiple --jobs does not spawn an excessive number of compiler processes. The jobserver is on by default and can be turned off with --jobserver false.

• Fixed: Don't error on diffs containing a "Binary files differ" message.

v24.7.1

• Changed: No build timeouts by default. Previously, cargo-mutants set a default build timeout based on the baseline build, but experience showed that this would sometimes make builds flaky, because build times can be quite variable. If mutants cause builds to hang, then you can still set a timeout using --build-timeout or --build-timeout-multiplier.

• Fixed: Don't error if the --in-diff file is empty.

• Changed: cargo-mutants no longer passes --cap-lints=allow to rustc. This was previously done so that mutants would not unnecessarily be unviable due to triggering compiler warnings in trees configured to deny some lints, but it had the undesirable effect of disabling rustc's detection of long running const evaluations. If your tree treats some lints as errors then the previous behavior can be restored with --cap-lints=true (or the equivalent config option), or you can use cfg_attr and a feature flag to accept those warnings when testing under cargo-mutants.

Download cargo-mutants 24.7.1

File	Platform	Checksum
cargo-mutants-aarch64-apple-darwin.tar.xz	Apple Silicon macOS	checksum
cargo-mutants-x86_64-apple-darwin.tar.xz	Intel macOS	checksum
cargo-mutants-x86_64-pc-windows-msvc.zip	x64 Windows	checksum
cargo-mutants-x86_64-unknown-linux-gnu.tar.xz	x64 Linux	checksum

v24.7.0

Download cargo-mutants 24.7.0

File	Platform	Checksum
cargo-mutants-aarch64-apple-darwin.tar.xz	Apple Silicon macOS	checksum
cargo-mutants-x86_64-apple-darwin.tar.xz	Intel macOS	checksum
cargo-mutants-x86_64-pc-windows-msvc.zip	x64 Windows	checksum
cargo-mutants-x86_64-unknown-linux-gnu.tar.xz	x64 Linux	checksum

v24.5.0

• Fixed: Follow path attributes on mod statements.

• New: --build-timeout and --build-timeout-multiplier options for setting timeouts for the build and check cargo phases.

• Changed: --timeout-multiplier now overrides timeout_multiplier from .cargo/mutants.toml.

• Changed: --timeout and --timeout-multiplier are now conflicting options.

v24.4.0

• New: Generate mutations that delete the ! and - unary operators.

• Changed: Baselines and mutants are now built with cargo test --no-run rather than cargo build --tests as previously. This avoids wasted build effort if the dev and test Cargo profiles are not the same, and may better distinguish build failures from test failures. With --test-tool=nextest, the corresponding cargo nextest run --no-run is used.

• Fixed: .ignore files can no longer affect source tree copying, so test files listed in a .ignore (e.g. *.snap for Insta snapshots) are now correctly copied into temporary build directories.

• Fixed: Don't visit files marked with #![cfg(test)] (or other inner attributes that generally cause code to be skipped.)

• Fixed: Paths to module files nested within mod blocks are now correctly resolved.

• Added: Document stability policy in the manual.

v24.3.0

Download cargo-mutants 24.3.0

File	Platform	Checksum
cargo-mutants-aarch64-apple-darwin.tar.xz	Apple Silicon macOS	checksum
cargo-mutants-x86_64-apple-darwin.tar.xz	Intel macOS	checksum
cargo-mutants-x86_64-pc-windows-msvc.zip	x64 Windows	checksum
cargo-mutants-x86_64-unknown-linux-gnu.tar.xz	x64 Linux	checksum

v24.2.1

• New: --features, --no-default-features and --all-features options are passed through to Cargo.

• Changed: Minimum Rust version (to build cargo-mutants, not to use it) increased to 1.73.

• New: Warn if nextest returns an exit code indicating some failure other than test failure, such as an internal error in nextest.

• New: json output includes the exit code of subprocesses, and the signal if it was killed by a signal.

• Changed: Set INSTA_FORCE_PASS=0 (in addition to previously INSTA_UPDATE=no) when running tests, so that tests that use the Insta library don't write updates back into the source directory, and so don't falsely pass.

• New: --timeout-multiplier option allows setting the timeout for mutants to be a multiple of the baseline timeout, rather than a fixed time.

Install cargo-mutants 24.2.1

Install prebuilt binaries via shell script

curl --proto '=https' --tlsv1.2 -LsSf https://github.com/sourcefrog/cargo-mutants/releases/download/v24.2.1/cargo-mutants-installer.sh | sh

Install prebuilt binaries via powershell script

irm https://github.com/sourcefrog/cargo-mutants/releases/download/v24.2.1/cargo-mutants-installer.ps1 | iex

Download cargo-mutants 24.2.1

File	Platform	Checksum
cargo-mutants-aarch64-apple-darwin.tar.xz	Apple Silicon macOS	checksum
cargo-mutants-x86_64-apple-darwin.tar.xz	Intel macOS	checksum
cargo-mutants-x86_64-pc-windows-msvc.zip	x64 Windows	checksum
cargo-mutants-x86_64-unknown-linux-gnu.tar.xz	x64 Linux	checksum

v24.2.0

• New: Colored output can be enabled in CI or other noninteractive situations by passing --colors=always, or setting CARGO_TERM_COLOR=always, or CLICOLOR_FORCE=1. Colors can similarly be forced off with --colors=never, CARGO_TERM_COLOR=never, or NO_COLOR=1.

Install cargo-mutants 24.2.0

Install prebuilt binaries via shell script

curl --proto '=https' --tlsv1.2 -LsSf https://github.com/sourcefrog/cargo-mutants/releases/download/v24.2.0/cargo-mutants-installer.sh | sh

Install prebuilt binaries via powershell script

irm https://github.com/sourcefrog/cargo-mutants/releases/download/v24.2.0/cargo-mutants-installer.ps1 | iex

Download cargo-mutants 24.2.0

File	Platform	Checksum
cargo-mutants-aarch64-apple-darwin.tar.xz	Apple Silicon macOS	checksum
cargo-mutants-x86_64-apple-darwin.tar.xz	Intel macOS	checksum
cargo-mutants-x86_64-pc-windows-msvc.zip	x64 Windows	checksum
cargo-mutants-x86_64-unknown-linux-gnu.tar.xz	x64 Linux	checksum

v24.1.2

• New: --in-place option tests mutations in the original source tree, without copying the tree. This is faster and uses less disk space, but it's incompatible with --jobs, and you must be careful not to edit or commit the source tree while tests are running.

---

Install cargo-mutants 24.1.2

Install prebuilt binaries via shell script

curl --proto '=https' --tlsv1.2 -LsSf https://github.com/sourcefrog/cargo-mutants/releases/download/v24.1.2/cargo-mutants-installer.sh | sh

Install prebuilt binaries via powershell script

irm https://github.com/sourcefrog/cargo-mutants/releases/download/v24.1.2/cargo-mutants-installer.ps1 | iex

Download cargo-mutants 24.1.2

File	Platform	Checksum
cargo-mutants-aarch64-apple-darwin.tar.xz	macOS Apple Silicon	checksum
cargo-mutants-x86_64-apple-darwin.tar.xz	macOS Intel	checksum
cargo-mutants-x86_64-pc-windows-msvc.zip	Windows x64	checksum
cargo-mutants-x86_64-unknown-linux-gnu.tar.xz	Linux x64	checksum

v24.1.1

cargo-mutants 24.1.1

• New: Mutate +, -, *, /, %, &, ^, |, <<, >> binary ops, and their corresponding assignment ops like +=.

• New: --baseline=skip option to skip running tests in an unmutated tree, when they're already been checked externally.

• Changed: Stop generating mutations of || and && to != and ||, because it seems to raise too many low-value false positives that may be hard to test.

• Fixed: Colors in command-line help and error messages.

---

Install cargo-mutants 24.1.1

Install prebuilt binaries via shell script

curl --proto '=https' --tlsv1.2 -LsSf https://github.com/sourcefrog/cargo-mutants/releases/download/v24.1.1/cargo-mutants-installer.sh | sh

Install prebuilt binaries via powershell script

irm https://github.com/sourcefrog/cargo-mutants/releases/download/v24.1.1/cargo-mutants-installer.ps1 | iex

Download cargo-mutants 24.1.1

File	Platform	Checksum
cargo-mutants-aarch64-apple-darwin.tar.xz	macOS Apple Silicon	checksum
cargo-mutants-x86_64-apple-darwin.tar.xz	macOS Intel	checksum
cargo-mutants-x86_64-pc-windows-msvc.zip	Windows x64	checksum
cargo-mutants-x86_64-unknown-linux-gnu.tar.xz	Linux x64	checksum