Systemd Merges Support for Rust Programs

October 26, 2026

“As of today in systemd Git it’s now possible for the systemd programs to be written in the Rust programming language as an alternative to C,” reports Phoronix:

Core systemd code like the systemd library doesn’t yet support Rust code, but for the various systemd programs / leaf components there is now support for using Rust… The new systemd-keyring-setup utility in Rust is used for provisioning keyrings and enrolling X.509 certificates into the kernel’s dm-verity / fs-verity / BPF keyrings during the boot process while dealing them afterward. This systemd-keyring-setup code hasn’t been merged yet but is expected soon now that the Rust infrastructure has landed. Originally it was all part of a single big commit before being split-up for the Rust enablement, systemd-keyring-setup, and other preparations for this new component.

Systemd developers aren’t planning on porting existing C code to Rust, all the Rust code is built with Meson [no Cargo usage], and C linkage only is mandated.

Systemd Rust components come out slightly larger than C with a test program being 32KB compared to 20KB for its C twin. For now at least the systemd Rust support is optional and toggled by the -Drust= Meson option with it being auto by default.