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bors 006c8df322 Auto merge of - oli-obk:supports_feature, r=wesleywiser
allow overwriting the output of `rustc --version`

Our wonderful bisection folk [have to work around](https://github.com/rust-lang/rust/issues/123276#issuecomment-2075001510) crates that do incomplete nightly/feature detection, as otherwise the bisection just points to where the feature detection breaks, and not to the actual breakage they are looking for.

This is also annoying behaviour to nightly users who did not opt-in to those nightly features. Most nightly users want to be in control of the nightly breakage they get, by

* choosing when to update rustc
* choosing when to update dependencies
* choosing which nightly features they are willing to take the breakage for

The reason this breakage occurs is that the build script of some crates run `rustc --version`, and if the version looks like nightly or dev, it will enable nightly features. These nightly features may break in random ways whenever we change something in nightly, so every release of such a crate will only work with a small range of nightly releases. This causes bisection to fail whenever it tries an unsupported nightly, even though that crate is not related to the bisection at all, but is just an unrelated dependency.

This PR (and the policy I want to establish with this FCP) is only for situations like the `version_check`'s `supports_feature` function. It is explicitly not for `autocfg` or similar feature-detection-by-building-rust-code, irrespective of my opinions on it and the similarity of nightly breakage that can occur with such schemes. These cause much less breakage, but should the breakage become an issue, they should get covered by this policy, too.

This PR allows changing the version and release strings reported by `rustc --version` via the `RUSTC_OVERRIDE_VERSION_STRING` env var. The bisection issue is then fixed by https://github.com/rust-lang/cargo-bisect-rustc/pull/335.

I mainly want to establish a compiler team policy:

> We do not consider feature detection on nightly (on stable via compiler version numbering is fine) a valid use case that we need to support, and if it causes problems, we are at liberty to do what we deem best - either actively working to prevent it or to actively ignore it. We may try to work with responsive and cooperative authors, but are not obligated to.

Should they subvert the workarounds that nightly users or cargo-bisect-rustc can use, we should be able to land rustc PRs that target the specific crates that cause issues for us and outright replace their build script's logic to disable nightly detection.

I am not including links to crates, PRs or issues here, as I don't actually care about the specific use cases and don't want to make it trivial to go there and leave comments. This discussion is going to be interesting enough on its own, without branching out.
2024-07-30 15:25:31 +00:00
.github Move rustbook to its own workspace. 2024-07-22 07:20:57 -07:00
compiler Auto merge of - oli-obk:supports_feature, r=wesleywiser 2024-07-30 15:25:31 +00:00
library Auto merge of - matthiaskrgr:rollup-i3qz9uo, r=matthiaskrgr 2024-07-30 05:50:05 +00:00
LICENSES Include REUSE.toml in REUSE.toml. 2024-07-22 09:44:18 +01:00
src Auto merge of - oli-obk:supports_feature, r=wesleywiser 2024-07-30 15:25:31 +00:00
tests Auto merge of - oli-obk:supports_feature, r=wesleywiser 2024-07-30 15:25:31 +00:00
.clang-format Add .clang-format 2024-06-26 05:56:00 +08:00
.editorconfig Only use max_line_length = 100 for *.rs 2023-07-10 15:18:36 -07:00
.git-blame-ignore-revs Ignore compiletest test directive migration commits 2024-02-22 18:55:02 +00:00
.gitattributes Rename config.toml.example to config.example.toml 2023-03-11 14:10:00 -08:00
.gitignore Don't output test artifacts into working directory 2024-07-21 13:45:55 -04:00
.gitmodules refactor: add rustc-perf submodule to src/tools 2024-05-20 14:56:49 +00:00
.ignore Add .ignore file to make config.toml searchable in vscode 2024-06-24 10:15:16 +02:00
.mailmap trans her gender 2024-07-27 23:36:23 +00:00
Cargo.lock rustdoc: word wrap CamelCase in the item list table 2024-07-29 08:45:50 -07:00
Cargo.toml Bump Clippy version -> 0.1.82 2024-07-25 18:23:37 +02:00
CODE_OF_CONDUCT.md Remove the code of conduct; instead link https://www.rust-lang.org/conduct.html 2019-10-05 22:55:19 +02:00
config.example.toml update rust.channel documentation 2024-07-27 11:08:29 +03:00
configure Ensure ./configure works when configure.py path contains spaces 2024-02-16 18:57:22 +00:00
CONTRIBUTING.md fix: Update CONTRIBUTING.md recommend -> recommended 2023-11-16 23:57:09 +05:30
COPYRIGHT Update COPYRIGHT file 2022-10-30 10:23:14 -04:00
INSTALL.md Rollup merge of - onur-ozkan:use-bootstrap-instead-of-rustbuild, r=Mark-Simulacrum 2024-07-13 20:19:45 -07:00
LICENSE-APACHE Remove appendix from LICENCE-APACHE 2019-12-30 14:25:53 +00:00
LICENSE-MIT LICENSE-MIT: Remove inaccurate (misattributed) copyright notice 2017-07-26 16:51:58 -07:00
README.md Use SVG logos in the README.md. 2024-04-03 19:48:20 +02:00
RELEASES.md Fix 1.80.0 version in RELEASES.md 2024-07-25 16:57:57 +02:00
REUSE.toml Include REUSE.toml in REUSE.toml. 2024-07-22 09:44:18 +01:00
rust-bors.toml Increase timeout for new bors bot 2024-03-13 08:31:07 +01:00
rustfmt.toml Update use declarations formatting options. 2024-07-29 08:26:08 +10:00
triagebot.toml triagebot: make sure Nora is called Nora 2024-07-29 17:01:39 +00:00
x Make x capable of resolving symlinks 2023-10-14 17:53:33 +03:00
x.ps1 use & instead of start-process in x.ps1 2023-12-09 09:46:16 -05:00
x.py Fix recent python linting errors 2023-08-02 04:40:28 -04:00

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 integrate 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).

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Read "Installation" from The Book.

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