58b2d609ec
stdlib crates get a SourceId which has an absolute path pointing into the sysroot. This makes the metadata hash change depending on where you've installed Rust. This is causing problems because the different hashes snowball into the optimizer making different decisions which ends up changing the binary size. (Some context: at work we're working with embedded devices with little flash storage so it often happens that a binary builds locally and then fails to fit in flash in CI, just because CI has installed rustc to a different path. Improving binary size is *not* a goal of this PR, after the fix the size will be whatever, but at least it won't change based on the rustc path anymore) Overview of the fix: - For libstd crates, the metadata hash now contains the path relative to the sysroot, instead of the absolute path. - The absolute path is still hashed into the fingerprint (not the metadata) so moving the rustc installation triggers a rebuild. This ensures stdlib crates are rebuilt when upgrading nightly versions. - The rustc version is still hashed into the metadata as usual, so upgrading Rust releases (not nightly versions) does cause a metadata change. Repro of the bug: ``` $ git clone https://github.com/embassy-rs/embassy --branch cargo-nondet-repro $ cd embassy/ $ cd examples/nrf52840 $ RUSTUP_HOME=~/.rustup1 cargo build --release --bin wifi_esp_hosted .... Finished `release` profile [optimized + debuginfo] target(s) in 13.33s $ llvm-size target/thumbv7em-none-eabi/release/wifi_esp_hosted text data bss dec hex filename 114500 80 48116 162696 27b88 target/thumbv7em-none-eabi/release/wifi_esp_hosted $ RUSTUP_HOME=~/.rustup2 cargo build --release --bin wifi_esp_hosted .... Finished `release` profile [optimized + debuginfo] target(s) in 9.64s $ llvm-size target/humbv7em-none-eabi/release/wifi_esp_hosted text data bss dec hex filename 114272 80 48116 162468 27aa4 target/thumbv7em-none-eabi/release/wifi_esp_hosted ```
Cargo
Cargo downloads your Rust project’s dependencies and compiles your project.
To start using Cargo, learn more at The Cargo Book.
To start developing Cargo itself, read the Cargo Contributor Guide.
The Cargo binary distributed through with Rust is maintained by the Cargo team for use by the wider ecosystem. For all other uses of this crate (as a binary or library) this is maintained by the Cargo team, primarily for use by Cargo and not intended for external use (except as a transitive dependency). This crate may make major changes to its APIs.
Code Status
Code documentation: https://doc.rust-lang.org/nightly/nightly-rustc/cargo/
Compiling from Source
Requirements
Cargo requires the following tools and packages to build:
cargoandrustc- A C compiler for your platform
git(to clone this repository)
Other requirements:
The following are optional based on your platform and needs.
-
pkg-config— This is used to help locate system packages, such aslibsslheaders/libraries. This may not be required in all cases, such as using vendored OpenSSL, or on Windows. -
OpenSSL — Only needed on Unix-like systems and only if the
vendored-opensslCargo feature is not used.This requires the development headers, which can be obtained from the
libssl-devpackage on Ubuntu oropenssl-develwith apk or yum or theopensslpackage from Homebrew on macOS.If using the
vendored-opensslCargo feature, then a static copy of OpenSSL will be built from source instead of using the system OpenSSL. This may require additional tools such asperlandmake.On macOS, common installation directories from Homebrew, MacPorts, or pkgsrc will be checked. Otherwise it will fall back to
pkg-config.On Windows, the system-provided Schannel will be used instead.
LibreSSL is also supported.
Optional system libraries:
The build will automatically use vendored versions of the following libraries. However, if they are provided by the system and can be found with pkg-config, then the system libraries will be used instead:
libcurl— Used for network transfers.libgit2— Used for fetching git dependencies.libssh2— Used for SSH access to git repositories.libz(aka zlib) — Used for data compression.
It is recommended to use the vendored versions as they are the versions that are tested to work with Cargo.
Compiling
First, you'll want to check out this repository
git clone https://github.com/rust-lang/cargo.git
cd cargo
With cargo already installed, you can simply run:
cargo build --release
Adding new subcommands to Cargo
Cargo is designed to be extensible with new subcommands without having to modify Cargo itself. See the Wiki page for more details and a list of known community-developed subcommands.
Releases
Cargo releases coincide with Rust releases. High level release notes are available as part of Rust's release notes. Detailed release notes are available in this repo at CHANGELOG.md.
Reporting issues
Found a bug? We'd love to know about it!
Please report all issues on the GitHub issue tracker.
Contributing
See the Cargo Contributor Guide for a complete introduction to contributing to Cargo.
License
Cargo is primarily distributed under the terms of both the MIT license and the Apache License (Version 2.0).
See LICENSE-APACHE and LICENSE-MIT for details.
Third party software
This product includes software developed by the OpenSSL Project for use in the OpenSSL Toolkit (https://www.openssl.org/).
In binary form, this product includes software that is licensed under the terms of the GNU General Public License, version 2, with a linking exception, which can be obtained from the upstream repository.
See LICENSE-THIRD-PARTY for details.