Deprecate RUST_TEST_* env variables Like with rust-lang/rust#139224, this is a documentation-only deprecation for now. Over time, we can - warn and then remove on use of unstable environment variables - warn on use of stable environment variables (no plan to remove due to compatibility) Longer term, we expect test runners, like `cargo test`, to provide the necessary mechanisms for environmental or persistent configuration (e.g. using cargo config which supports `.cargo/config.toml` as well as environment variables). This would include: - `RUST_TEST_THREADS` - `RUST_TEST_NOCAPTURE` - `RUST_TEST_SHUFFLE` (unstable) - `RUST_TEST_SHUFFLE_SEED` (unstable) The primary outcomes for this change are - Reducing the scope of what is expected for custom test harnesses to implement - Reduce the mechanisms that test runners, like `cargo test`, are expected to track when they are being bypassed to protect against negative interactions, e.g. `RUST_TEST_NOCAPTURE=1` when json output is being read. For testing-devex FCP, see rust-lang/testing-devex-team#10 Fixes rust-lang/testing-devex-team#10 History ------- At each step, I could not find evidence of design discussions on whether to support CLI, env, or both. The first env variable seems to come from the fact that it was being forked out of an existing env variable that had a much wider scope. At best, this seems like a way to offer a more persistent configuration for these flags but environment variables hidden away in libtest is a bit clunky and this seems like the wrong layer to handle this problem. **Originally:** `RUST_THREADS` was respected by the Rust runtime and libextra/test got this for free **2013:** rust-lang/rust#7335 suggested splitting `RUST_TEST_TASKS` out of `RUST_THREADS`. In that issue and the implementation (rust-lang/rust#8823). **2014:** rust-lang/rust#13374 ask for support to disable capturing of stdout/stderr. `--nocapture` and `RUST_TEST_NOCAPTURE` were added together. **2015:** rust-lang/rust#23525 renamed `RUST_TEST_TASKS` to `RUST_TEST_THREADS` **2016:** rust-lang/rust#25636 asked to configure `RUST_TEST_THREADS` via `--test-threads` which was implemented in rust-lang/rust#35414 **2021:** rust-lang/rust#85440 asked for test randomization which was implemented in rust-lang/rust#89082, adding `--shuffle` / RUST_TEST_SHUFFLE` and `--shuffle-seed SEED` / `RUST_TEST_SHUFFLE_SEED` Potentially relevant issues --------------------------- - rust-lang/rust#74845
This is the main source code repository for Rust. It contains the compiler, standard library, and documentation.
Why Rust?
-
Performance: Fast and memory-efficient, suitable for critical services, embedded devices, and easily integrated with other languages.
-
Reliability: Our rich type system and ownership model ensure memory and thread safety, reducing bugs at compile-time.
-
Productivity: Comprehensive documentation, a compiler committed to providing great diagnostics, and advanced tooling including package manager and build tool (Cargo), auto-formatter (rustfmt), linter (Clippy) and editor support (rust-analyzer).
Quick Start
Read "Installation" from The Book.
Installing from Source
If you really want to install from source (though this is not recommended), see INSTALL.md.
Getting Help
See https://www.rust-lang.org/community for a list of chat platforms and forums.
Contributing
See CONTRIBUTING.md.
License
Rust is primarily distributed under the terms of both the MIT license and the Apache License (Version 2.0), with portions covered by various BSD-like licenses.
See LICENSE-APACHE, LICENSE-MIT, and COPYRIGHT for details.
Trademark
The Rust Foundation owns and protects the Rust and Cargo trademarks and logos (the "Rust Trademarks").
If you want to use these names or brands, please read the Rust language trademark policy.
Third-party logos may be subject to third-party copyrights and trademarks. See Licenses for details.