RACER = Rust Auto-Complete-er. A utility intended to provide Rust code completion for editors and IDEs. Maybe one day the 'er' bit will be exploring + refactoring or something.

Racer is not actively developped now. Please consider using newer software such as rust-analyzer.

NOTE From 2.1, racer needs nightly rust

If you're using rustup, run

rustup toolchain install nightly
rustup component add rustc-dev --toolchain=nightly

Note: The second command adds the rustc-dev component to the nightly toolchain, which is necessary to compile Racer.

Internally, racer calls cargo as a CLI tool, so please make sure cargo is installed

Simply run:

cargo +nightly install racer

As mentioned in the command output, don't forget to add the installation directory to your PATH.

1. Clone the repository: git clone https://github.com/racer-rust/racer.git

2. cd racer; cargo +nightly build --release. The binary will now be in ./target/release/racer

3. Add the binary to your PATH. This can be done by moving it to a directory already in your PATH (i.e. /usr/local/bin) or by adding the ./target/release/ directory to your PATH

1. Fetch the Rust sourcecode

   1. automatically via rustup and run rustup component add rust-src in order to install the source to $(rustc --print sysroot)/lib/rustlib/src/rust/library (or $(rustc --print sysroot)/lib/rustlib/src/rust/src in older toolchains). Rustup will keep the sources in sync with the toolchain if you run rustup update.

   2. manually from git: https://github.com/rust-lang/rust

   Note

   If you want to use racer with multiple release channels (Rust has 3 release channels: stable, beta and nightly), you have to also download Rust source code for each release channel you install.

   e.g. (rustup case) Add a nightly toolchain build and install nightly sources too

   rustup toolchain add nightly

   rustup component add rust-src

2. (Optional) Set RUST_SRC_PATH environment variable to point to the 'src' dir in the Rust source installation e.g. % export RUST_SRC_PATH=$(rustc --print sysroot)/lib/rustlib/src/rust/library or % export RUST_SRC_PATH="$(rustc --print sysroot)/lib/rustlib/src/rust/src" (older)

   It's recommended to set RUST_SRC_PATH for speed up, but racer detects it automatically if you don't set it.

3. Test on the command line:

   racer complete std::io::B (should show some completions)

Note

To complete names in external crates, Racer needs Cargo.lock. So, when you add a dependency in your Cargo.toml, you have to run a build command such as cargo build or cargo test, to get completions.

Racer is used as a static library in RLS

Racer can be used with Eclipse through the use of RustDT. (User guide is linked in repo description)

Emacs integration has been moved to a separate project: emacs-racer.

Gedit integration can be found here.

Gnome Builder integration can be found here

The Kate community maintains a plugin. It is bundled with recent releases of Kate (tested with 16.08 - read more here).

1. Enable 'Rust code completion' in the plugin list in the Kate config dialog;

2. On the new 'Rust code completion' dialog page, make sure 'Racer command' and 'Rust source tree location' are set correctly.

The Sublime Text community maintains some packages that integrates Racer

• RustAutoComplete that offers auto completion and goto definition.
• AnacondaRUST from the anaconda plugins family that offers auto completion, goto definition and show documentation

Vim integration has been moved to a separate project: vim-racer.

Racer recommends the official Rust (rls) extension based on RLS, which uses Racer for completion.

You can find the racer package for Atom here

Kakoune comes with a builtin integration for racer auto completion.