Systemd merges support for new Rust leaf components

Christian Brauner announced on Mastodon that support for writing leaf components of systemd in Rust has been merged. The previous effort, pull request #44144, was split into five separate parts. Part 1 includes keyring-util and voa-util, described as helpers for enrolling certificates into kernel keyrings. Part 2 provides support programs written in Rust. The work is expected to appear in the systemd v263 release, which is scheduled for December.

Rust will be used only for new leaf components, and existing code is not being ported. Nothing that other components depend on is written in Rust. The project aims to move forward with Rust support in core systemd but faces blockers regarding dynamic libraries. The team noted that Rust's current support for dynamic libraries is insufficient for this purpose.

The build process does not use the cargo package manager; everything is built with meson. Any Rust code must not use the standard library. The system requires Rust version 1.85 or later. The project documents a requirement for bindgen version 0.71.1 or newer and Meson version 1.4.0.