Install PL/Rust Prerequisites

These instructions explain how to install PL/Rust on a typical OS PostgreSQL installation installed using the OS' package manager. These instructions include steps for trusted and untrusted plrust and are tested using Ubuntu 22.04 and PostgreSQL 15. PostgreSQL 15 for this document is installed using apt using the pgdg repository. See the PostgreSQL apt wiki page for instructions.

Steps to install PL/Rust:

  • Prerequisites
  • Install Rust
  • Install pgrx
  • Install PL/Rust
  • Create amazing things!


PL/Rust requires PostgreSQL and all prerequisites outlined for pgrx are installed.

PL/Rust also requires that any databases in which it's created is UTF8. Postgres' default encoding is determined by the locale of the environment when initdb is first run. Depending on your operating system configuration, this may not resolve to UTF8.

Building PL/Rust from source requires installing cargo-pgrx which requires a development toolchain capable of building Postgres itself.


Installing PL/Rust with these instructions installs rustc, pgrx, and plrust as the Linux postgres user. The postgres user is created during the standard PostgreSQL installation via apt. For pgrx to successfully install plrust, the postgres user needs ownership of the extension and lib directories. The standard Ubuntu locations are indicated below.

sudo chown postgres -R /usr/share/postgresql/15/extension/
sudo chown postgres -R /usr/lib/postgresql/15/lib/

These permissions are later reset back to being owned by root in the Reset Permissions section.

Install rustc

Installing PL/Rust requires that the rustc compiler is available to the user installing it. Switch to the postgres Linux user and change into its home directory.

sudo su - postgres

The typically installation for rustc uses curl and rustup. If you want to install rustc without using rustup see the Other Rust installation methods page.

curl --proto '=https' --tlsv1.2 -sSf | sh

The rustup installer prompts for an installation choice. The default installation (1) should work for most use cases.

1) Proceed with installation (default)
2) Customize installation
3) Cancel installation

After installing rust, use exit to log out and back in to the postgres account. This ensures your terminal is using the newly installed rustc installation.

# Log in  as postgres fresh with rustc installed
sudo su - postgres

Clone plrust and check Rust version

PL/Rust is installed from source code using pgrx. This installation requires that pgrx is compiled using a specific version of rustc. The rustc version required for PL/Rust is defined in the project's rust-toolchain.toml. The steps below ensure the proper versions are used.

Clone the plrust repo from GitHub and change into the plrust/plrust directory. Running rustc -V in this location is used to verify the version reported is by rustc -V is the version defined by PL/Rust.

git clone
cd plrust/plrust
rustc -V

The output from rustc -V should look similar to the following example.

rustc 1.72.0 (90c541806 2023-05-31)

Use rustup default to check that the explicit version of rustc is selected. You need to see the version number reported in by rustc -V in your rustup default output.

rustup default

The expected output is below.

1.72.0-x86_64-unknown-linux-gnu (default)

If rustup default returns a different version number or stable, set the default version as shown below and check that the output updates accordingly.

rustup default 1.72.0
rustup default

Be careful with Rust versions

WARNING! The stable version of rustc cannot be used to install Trusted PL/Rust. This is the case even when the stable version is identical to the tagged version number, such as 1.72.0.

The above checks of rustc -V and rustup default are important to follow before installing pgrx and PL/Rust. You must install pgrx with the version of rustc that plrust expects in the rust-toolchain.toml. Failing to do so will result in a mismatched version error in a subsequent step.

A misconfigured rustup default results in errors when creating functions with trusted PL/Rust. The error can manifest as a problem in the postgrestd linking with the following error. This happens because Rust makes a distinction between the latest stable version of Rust, and the actual version of the stable release (e.g. 1.72.0), even when they refer to the same release.

Error loading target specification: Could not find specification for target "x86_64-postgres-linux-gnu".

Install pgrx

The PL/Rust extension is built and installed using pgrx. Install pgrx with the --locked option. This step takes a few minutes.

cargo install cargo-pgrx --locked

Pgrx needs to be initialized for use with the PostgreSQL installation. This is done using pgrx init. This step needs to know where your pg_config file is located at. If you have a standard Ubuntu apt installation of PostgreSQL with a single version of PostgreSQL installed you can use the generic /usr/bin/pg_config path.

cargo pgrx init --pg15 /usr/bin/pg_config

Output from cargo pgrx init looks like the following example. You may notice it mentions information about a new data directory under your user's ~/.pgrx/ directory. This does not replace your PostgreSQL instance's data directory. The ~/.pgrx/data-15/ directory is there in case you run cargo pgrx run pg15, which would use this custom data directory, not your installation's data directory.

   Validating /usr/bin/pg_config
 Initializing data directory at /var/lib/postgresql/.pgrx/data-15

The generic pg_config used above will not work for all installations, such as if you have both PostgreSQL 14 and 15 installed on one instance. In these cases you should specify the exact pg_config file for your installation.

cargo pgrx init --pg14 /usr/lib/postgresql/14/bin/pg_config

The instructions on this page have setup the prerequisite software required to install PL/Rust. The next section, Install PL/Rust, finishes the installation process.