74043673e6
Add '-C' flag for changing current dir before build This implements the suggestion in #10098 to make cargo change cwd before completing config processing and starting the build. It is also an alternative to `--manifest-path` that resolves the issue described in #2930. The behavior of this new flag makes cargo build function exactly the same when run at the root of the project as if run elsewhere outside of the project. This is in contrast to `--manifest-path`, which, for example, results in a different series of directories being searched for `.cargo/config.toml` between the two cases. Fixes #10098 Reduces impact of #2930 for many, possibly all impacted, by switching to this new cli argument. ### How should we test and review this PR? The easiest way to reproduce the issue described in #2930 is to create an invalid `.cargo/config.toml` file in the root of a cargo project, for example `!` as the contents of the file. Running cargo with the current working directory underneath the root of that project will quickly fail with an error, showing that the config file was processed. This is correct and expected behavior. Running the the same build with the current working directory set outside of the project, e.g. /tmp, and passing the `--manifest-path /path/to/project/Cargo.toml`. The build will proceed without erroring as a result of reading the project's `.cargo/config.toml`, because config file searching is done from cwd (e.g. in `/tmp` and `/`) without including the project root, which is a surprising result in the context of the [cargo config documentation](https://doc.rust-lang.org/cargo/reference/config.html), which suggests that a `.cargo/config.toml` file checked into the root of a project's revision control will be processed during the build of that project. Finally to demonstrate that this PR results in the expected behavior, run cargo similar to the previous run, from /tmp or similar, but instead of `--manifest-path /path/to/project/Cargo.toml`, pass `-C/path/to/project` to cargo (note the missing `Cargo.toml` at the end). The build will provide the exact same (expected error) behavior as when running it within the project root directory. ### Additional information ~Passing a path with a trailing '/' will result in failure. It is unclear whether this is a result of improper input sanitization, or whether the config.cwd value is being improperly handled on output. In either case this needs to be resolved before this PR is merge-ready.~ (the above issue appears to have been a side effect of local corruption of my rustup toolchain, and unrelated to this change) Because a `struct Config` gets created before command line arguments are processed, a config will exist with the actual cwd recorded, and it must then be replaced with the new value after command line arguments are processed but before anything tries to use the stored cwd value or any other value derived from it for anything. This change effectively creates a difficult-to-document requirement during cargo initialization regarding the order of events. For example, should a setting stored in a config file discovered via cwd+ancestors search be wanted before argument processing happens, this could result in unpleasant surprises in the exact use case this feature is being added to fix. A long flag was deferred out to not block this on deciding what to name it. A follow up issue will be created.
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.
Code Status
Code documentation: https://docs.rs/cargo/
Installing Cargo
Cargo is distributed by default with Rust, so if you've got rustc installed
locally you probably also have cargo installed locally.
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.