cargo-lite 1.1.3

Rust package manager

cargo-lite v1.1.2

cargo-lite is an interim package manager for Rust that is sloppily designed and implemented, intended to have something that “just works” until there is a package manager that works reliably and well. This isn’t intended to grow into a production-quality package manager.

What does it do? It fetches dependencies and builds them. It can fetch from git, hg, or local directories. It doesn’t do any handling of versions etc. It will rebuild when dependencies change, as well as when rustc’s version changes.

Installation

You can use pip:

pip install cargo-lite

Or, you can do it manually, using distutils:

git clone https://github.com/cmr/cargo-lite.git
cd cargo-lite
sudo python setup.py install

Getting Help

You can find me on irc.mozilla.org as cmr. Look for me #rust-gamedev.

Contributing

Feel free to open issues or send pull requests. Pull requests should be against the dev branch.

How To Use cargo-lite

First, you need a cargo-lite.conf in the top-level directory of your repository. In it you will list your dependencies. You do this with a nested list:

deps = [
    ["--git", "http://github.com/bjz/gl-rs.git"]
,   ["--git", "http://github.com/bjz/glfw-rs.git"]
]

This specifies two dependencies: gl-rs and glfw-rs. It specifies that they should be cloned with git. cargo-lite install will read their top-level cargo-lite.conf, install all of their dependencies, and then build them, copying their build artifacts into the package depository (currently hardcoded as ~/.rust/lib). To build your own crate, you need an additional section in the cargo-lite.conf:

[build]
crate_root = "src/main.rs"

This tells cargo-lite to run rustc on src/main.rs. It will pass it the proper -L to link to its dependencies. You can add an additional directive to the build section to add flags:

[build]
crate_root = "src/main.rs"
rustc_args = ["-C", "prefer-dynamic"]

And that’s it, for simple crates! You can use cargo-lite build to build your crate. It will output the build artifacts in the same place as running rustc src/main.rs would. For building a library, you need to do:

[build]
crate_root = "src/lib.rs"
crate_type = "library"

For more complex projects, cargo-lite accepts the following directives:

subpackages = ["src/foo", "src/examples"]

[build]
build_cmd = "./build.sh"

cargo-lite.py will first recurse into the subpackages, installing those, and will then execute the build_cmd. Two environment variables will be added, which the build_cmd is expected to respect: CARGO_OUT_DIR, which is where artifacts to be installed must be copied to, and CARGO_RUSTFLAGS, which should be passed to rustc for all artifacts that are to be copied into CARGO_OUT_DIR. The CARGO_RUSTFLAGS will include things like -L /path/where/cargo-lite/libs/are/stored and optimization options.

cargo-lite.conf details

Top-level attributes

subpackages

A list of directories, relative to the directory this cargo-lite.conf is in, to recurse into and install. Note that subpackages installed unconditionally, and cannot fetch their source from a remote source. They provide a way to structure a single repository that has multiple crates in it. Subpackages are processed in order, and before any build instructions in build are executed.

build section

The build section describes how to build a package. If there are defined subpackages, this is optional. Otherwise, it is required. It has the following sub-attributes:

crate_root

A string. If specified, rustc will be invoked on this file, using the correct arguments (given the crate_type and rustc_args).

crate_type

A string. Either “binary” or “library”. Specifies whether the crate is to be built as a library or executable binary. Optional, the default is “binary”.

rustc_args

A list of strings. If specified, these arguments will be passed on to rustc when crate_root is specified, or joined with a single space and exported in the CARGO_RUSTFLAGS environment variable if build_cmd is specified.

hash_files

A list of strings. If specified, any files matching any of these globs will be hashed as part of determining whether a package should be rebuilt or not. By default, only *.rs is considered. Do note that this is, by nature, a quadratic algorithm. Take care not to specify many globs, and specifying the most common globs first. Since, on every build, every file in every dependency is hashed,

Only mtime is hashed, to try and keep time down. Due to the crate model, fine-grained dependency tracking isn’t particularly useful.

build_cmd

Either a string, or a list of strings. If just a string, it specifies the program that will carry out the building. If a list, the first argument is the program that will be executed, and the rest the arguments to that program.

At least one of crate_root and build_cmd must be specified. If both are specified, the build_cmd is run first, allowing for custom code generation. If neither is specified, processing will halt, and an error will be printed.

FAQ

Why Python?

Because it’s simple, ubiquitous, and most importantly, what I know.

Wow, this kinda sucks!

Yup! I don’t handle versioning, intelligent rebuilding, or anything of that sort. Pull requests accepted, but keep in mind that this is meant to be temporary, and not solve the hard problems of package management.

Non-goals

• Versioning of dependencies

• Build system beyond simply running rustc or a single shell command

• rustc integration beyond what is already present (no hooking into libsyntax etc)

• rust rewrite, or a rewrite into any other language

To-do

• Allow passing arbitrary rustc args

• Tests