While the Rust language has appeal for kernel development, many developers are
concerned by the fact that there is only one compiler available; there are
many reasons why a second implementation would be desirable. At the 2022
Kangrejos gathering, three developers
described projects to build Rust
programs with GCC in two different ways. A fully featured, GCC-based Rust
implementation is still going to take some time, but rapid progress is
being made.

Source: LWN.net – [$] Compiling Rust with GCC: an update