Installing Rust without root
I just got a good question from a friend on IRC: “Should I ask my university’s administration to install Rust on our shared servers?” The answer is “you don’t have to”.
Pick one of the two following sets of directions. I’d recommend using Multirust, because it automatically checks the packages it downloads and lets you switch between Rust versions trivially.
Without multirust
If you just want one version of Rust, this blog post by Valérian Galliat has a fix in 7 lines:
cd ~/.rust
wget https://static.rust-lang.org/dist/rust-nightly-x86_64-unknown-linux-gnu.tar.gz
tar xf rust-nightly-x86_64-unknown-linux-gnu.tar.gz
mv rust-nightly-x86_64-unknown-linux-gnu rust
export LD_LIBRARY_PATH=~/opt/rust/rustc/lib:$LD_LIBRARY_PATH
export PATH=~/.rust/rust/rustc/bin:$PATH
export PATH=~/.rust/rust/cargo/bin:$PATH
If you want rust stable instead of rust nightly, use the URL https://static.rust-lang.org/dist/rust-stable-x86_64-unknown-linux-gnu.tar.gz in the wget step to download the latest stable release.
If you’re security-conscious, you might want to verify the integrity of the tarball before inflating it and running its contents. We provide a GPG signature of every tarball, and sha256 sums of the tarballs and signatures.
You can construct the URL for shasum or GPG signature by adding the desired extension to the tarball’s URL, so for nightly:
https://static.rust-lang.org/dist/rust-nightly-x86_64-unknown-linux-gnu.tar.gz
https://static.rust-lang.org/dist/rust-nightly-x86_64-unknown-linux-gnu.tar.gz.sha256
https://static.rust-lang.org/dist/rust-nightly-x86_64-unknown-linux-gnu.tar.gz.asc
https://static.rust-lang.org/dist/rust-nightly-x86_64-unknown-linux-gnu.tar.gz.asc.sha256
To verify the GPG signature, you’ll also need a copy of the Rust project’s public key. This key is available through several channels:
- on the Rust website, available only over HTTPS.
- on keybase.io, correlated to Rust’s Twitter account and URL. Don’t worry, we authenticated the key by signing a string from Keybase with it locally. We don’t trust them to ever see our private key.
- on GitHub, in the website’s repository.
Remember, verifying the signature only guarantees that the tarball you downloaded matches the one that was produced by the Rust project’s build infrastructure. As with any piece of software, there exist a variety of threat models from which verifying the signatures cannot completely protect you.
Multirust without root
Multirust is a tool that makes it easy to use multiple Rust versions on the same system. Although the absolute easiest way to use it is curl -sf https://raw.githubusercontent.com/brson/multirust/master/blastoff.sh | sh (which will interactively request a sudo password partway through), it can be installed without root as well:
git clone --recursive https://github.com/brson/multirust && cd multirust
./build.sh # create install.sh
mkdir ~/.rust
./install.sh --prefix=~/.rust/
echo "PATH=~/.rust/bin:$PATH" >> ~/.bashrc; source ~/.bashrc
If you run into an error like:
install: WARNING: failed to run ldconfig. this may happen when not installing
as root. run with --verbose to see the error
or in verbose mode,:
install: running ldconfig
/sbin/ldconfig.real: Can't create temporary cache file /etc/ld.so.cache~:
Permission denied
install: WARNING: failed to run ldconfig. this may happen when not installing
as root. run with --verbose to see the error
It means you don’t have permissions to write to /etc/ld.so.cache. Until this issue gets fixed, the easiest workaround to lacking those permissions is to change the script called by the installer to pass -C to ldconfig:
sed -i 's/ ldconfig/ ldconfig -C ~\/.rust\/ld.so.cache/' build/work/multirust-0.7.0/install.sh
Then you should be able to ./install.sh --prefix=~/.rust without the prior warning. Nasty hack, but the easiest way to get it working today.
This technically breaks rustc (since it’s dynamically linked), but if you’re building a Rust project or library, you’ll be using the statically linked cargo tool and thus won’t be affected.
By the way, this is an example of why people who write system utilities like ldconfig should make them able to read their serttings out of environment variables as well as just command-line arguments.
Now you can multirust default nightly to install rust-nightly and configure it as the default, and you’re ready to roll!
Testing your Rust installation
You can now make a package that says “Hello World” in just 5 commands, using a workflow that will scale to packaging and distributing larger projects:
cargo new hello --bin
echo "fn main(){println!(\"Hello World\");}" > hello/src/main.rs
cd hello
cargo build
cargo run
Congratulations, you’re running Rust!