Hello World - installing Rust on RHEL 7

Introduction and Prerequisites

In this tutorial, you will install the Rust 1.31 Toolset and build a simple Rust Hello World application. This tutorial should take less than 30 minutes to complete.

Before you begin, you will need a current Red Hat Enterprise Linux 7 workstation or server subscription that allows you to download software and get updates from Red Hat. If you don’t have an active subscription, register and obtain the Red Hat Developer subscription (includes RHEL server) from here.

NOTE: The Rust Compiler naming convention has changed so that the version number reflects the community version. The previous version was Rust-toolset-7 which was based on Rust 1.29.

If you encounter difficulties at any point, see Troubleshooting and FAQ.

1. Enable necessary software repositories

In this step, you will configure and “register” your system to obtain software from the devtools repository by using the command line interface. 

Note: registering a subscription (the steps to follow) is different than registering for the Red Hat Developer Program (which you’ve likely done by now).

You can add or remove software repositories from the command line using the subscription-manager tool as the root user. Use the --list option to view the available software repositories and verify that you have access to the devtools repo.

$ su -
# subscription-manager repos --list | egrep devtools

If you don’t see any devtools repositories in the list, your subscription might not include it. See Troubleshooting and FAQ for more information.

If you are using a desktop edition of Red Hat Enterprise Linux, change -server- to -desktop- in the following commands:

# subscription-manager repos --enable rhel-7-server-devtools-rpms
# subscription-manager repos --enable rhel-server-rhscl-7-rpms

Add the Red Hat Developer Tools key to your system:

# cd /etc/pki/rpm-gpg
# wget -O RPM-GPG-KEY-redhat-devel https://www.redhat.com/security/data/a5787476.txt
# rpm --import RPM-GPG-KEY-redhat-devel

2. Setup your development environment

In this next step you will use a single command to download the Rust compiler. The length of time this step takes depends on the speed of your Internet connection and your system. With a reasonably fast connection, this step should complete in well under 5 minutes.

$ su -
# yum install rust-toolset-1.31

In Rust Toolset, cargo is provided by the rust-toolset-1.31-cargo package and is automatically installed with the rust-toolset-1.31 package.

3. Hello World and your first Rust application

Create and run the sample C++ Hello World projects

The following steps will create and run a Rust Hello World project

Using Rust from the command line

The Rust compiler (rustc) is not usually invoked directly, but through the cargo tool, like cargo build. You need to add Rust to your environment with scl enable in a Terminal window.

$ scl enable rust-toolset-1.31 bash

The simplest way to get started with a new project is using cargo new.  Create a hello executable project using “cargo new --bin hello”.  This will create a new directory with a Cargo.toml project manifest and the src/main.rs entry point for your program.

hello/Cargo.toml
   [package]
   name = "hello"
   version = "0.1.0"
   authors = ["I.M Coder <imc@redhat.com>"]

   [dependencies]

hello/src/main.rs
   fn main() {
       println!("Hello, world!");
   }

Now compile and run the program:

$ cd hello
$ cargo run
Hello, world!

Let’s customize that message.  Edit src/main.rs using a text editor such as vi, nano, or gedit, changing to the following content:

fn main() {
">println!("Hello, Red Hat Developer Program World!");
}

When making changes it’s often useful to get quick feedback from the compiler that your code will be accepted.  You can run cargo check for full syntax and type checking, without the longer delays for code generation.  Then when you’re ready, compile and run it again.

$ cargo run
Hello, Red Hat Developer Program World!

 

Troubleshooting and FAQ

1. As a developer, how can I get a Red Hat Enterprise Linux subscription that includes the Clang/LLVM, Go, or Rust Compilers?

Developers can get a no-cost Red Hat Enterprise Linux Developer subscription for development purposes by registering and downloading through developers.redhat.com. We recommend you follow our Getting Started Guide which covers downloading and installing Red Hat Enterprise Linux on a physical system or virtual machine (VM) using your choice of VirtualBox, VMware, Microsoft Hyper-V, or Linux KVM/Libvirt. For more information, see Frequently asked questions: no-cost Red Hat Enterprise Linux Developer subscription.

2. I can’t find the devtools or RHSCL repository on my system.

Some Red Hat Enterprise Linux subscriptions do not include access to Software Collections or development tools. For a list of what subscriptions are included see How to use Red Hat Software Collections (RHSCL), Red Hat Developer Toolset (DTS, etc.).

The name of the repository depends on whether you have a server or workstation version of Red Hat Enterprise Linux installed. You can use subscription-manager to view the available software repositories and verify that you have access to RHSCL and devtools:

$ su -
# subscription-manager repos --list | egrep rhscl
# subscription-manager repos --list | egrep devtools

 

3. When I run yum install package (go-toolset-7, llvm-toolset-7, rust-toolset-7), it fails due to a missing dependency.

Some software collections require packages that are in the devtools RPMs repository, which is not enabled by default. See Step 1 above, for how to enable both the applicable RPMs and repositories.

4. How can I view the Go manual pages?

The Go compiler help command provides information on its usage. To show the help index:

$ scl enable go-toolset-7 'go help'

5. How can I find out what RHSCL packages are installed?

scl --list will show the list of RHSCL packages that have been installed, whether they are enabled or not.

$ scl --list