cargo-hack
cargo-hack is a Rust CLI tool that extends Cargo with specialized testing and CI capabilities, including per-feature testing, feature powerset generation, and multi-version Rust validation. It automates complex test matrix scenarios that would otherwise require manual scripting.
Key facts
Objective fields from the source. Values we can't verify are shown as “Unknown” rather than guessed.
| Field | Value |
|---|---|
| Repository | taiki-e/cargo-hack |
| Owner | taiki-e |
| Primary language | Rust |
| License | Apache-2.0 — OSI-approved |
| Stars | 846 |
| Forks | 40 |
| Open issues | 42 |
| Latest release | v0.6.45 (2026-05-30) |
| Last updated | 2026-07-04 |
| Source | https://github.com/taiki-e/cargo-hack |
What cargo-hack is
A Cargo subcommand written in Rust that generates and executes test matrices across feature combinations (--each-feature, --feature-powerset), optional dependencies, Rust version ranges, and custom exclusion/grouping rules. It modifies Cargo.toml temporarily for no-dev-deps runs and supports workspace-level operations with optional partitioning.
Get the cargo-hack source
Clone the repository and explore it locally.
git clone https://github.com/taiki-e/cargo-hack.gitcd cargo-hack# follow the project's README for install & configurationNeed it deployed, integrated, or customized instead? DEV.co ships production installs.
Best use cases
Implementation considerations
- Requires Cargo 1.x; verify minimal version compatibility with your dependency lock strategy (--locked flag available for CI stability).
- Feature powerset generation grows exponentially; use --depth, --exclude-features, --mutually-exclusive-features to constrain matrix size and CI time.
- --no-dev-deps temporarily modifies Cargo.toml on disk; ensure CI has exclusive file access to avoid race conditions in parallel workflows.
- Partition feature (--partition M/N) supports distributed testing; integrate with CI matrix to distribute runs across jobs/runners.
- Version-range testing requires rustup or equivalent; configure CI image to support multiple Rust toolchains before invoking cargo-hack.
When to avoid it — and what to weigh
- Non-Rust projects — cargo-hack is Cargo-specific and cannot be applied to non-Rust build systems.
- Simple single-configuration testing needs — If your project has minimal feature flags or no MSRV concerns, cargo-hack adds unnecessary orchestration complexity over plain `cargo test`.
- Performance-critical CI where disk cleanup is forbidden — The --clean-per-run and --clean-per-version flags modify the build environment; some CI systems may require immutable artifact preservation.
- Teams unfamiliar with Cargo feature semantics — The tool requires understanding feature interactions, optional dependencies, and powerset logic; misuse can mask real bugs or produce false negatives.
License & commercial use
Licensed under Apache-2.0 OR MIT (dual license, as shown in README badge). Both are permissive OSI-approved licenses.
Both Apache-2.0 and MIT are permissive licenses that permit commercial use, modification, and distribution with minimal restrictions (attribution required). No commercial restrictions identified. However, for mission-critical CI tooling, verify compatibility with your internal license policies and consider upstream maintenance dependency.
DEV.co evaluation signals
Editorial assessment — not user reviews. Directional, with an explicit confidence level.
| Signal | Assessment |
|---|---|
| Maintenance | Active |
| Documentation | Strong |
| License clarity | Clear |
| Deployment complexity | Low |
| DEV.co fit | Good |
| Assessment confidence | High |
No identified security advisories in provided data. Tool runs arbitrary Cargo build commands; inherits Cargo's security model. Temporary Cargo.toml modifications (--no-dev-deps) are restored unless --remove-dev-deps used; review CI file permissions to prevent unauthorized modification. No network calls or external integration points identified. Supply chain risk: single maintainer; evaluate whether project activity and issue response meet your risk tolerance.
Alternatives to consider
nextest (nextest-rs/nextest)
Specialized test runner with partitioning and better failure output, but does not generate feature matrices; complementary rather than replacement.
Manual cargo script in CI (shell/Python)
Simpler for small matrix sizes but error-prone, harder to maintain, and lacks powerset/MSRV automation that cargo-hack provides.
Cargo-tree + custom CI logic
Can introspect features and build custom test strategies, but requires significant scripting; cargo-hack provides ready-made semantics.
Build on cargo-hack with DEV.co software developers
Evaluate cargo-hack in your CI pipeline: start with --each-feature to surface feature conflicts, then add --version-range for MSRV validation. Contact our Rust engineering team to optimize your CI strategy.
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cargo-hack FAQ
Does cargo-hack modify my actual Cargo.toml permanently?
How do I avoid feature powerset explosion?
Can I use cargo-hack outside of CI?
Does cargo-hack support non-Cargo Rust build systems?
Work with a software development agency
Need help beyond evaluating cargo-hack? DEV.co is a software development agency offering software development services and web development for teams of every size. Our software developers and web developers build custom software, web applications, APIs, and open-source testing integrations — and maintain them long-term.
Ready to Automate Your Rust Test Matrix?
Evaluate cargo-hack in your CI pipeline: start with --each-feature to surface feature conflicts, then add --version-range for MSRV validation. Contact our Rust engineering team to optimize your CI strategy.