The #Rust #bootstrap chain has shrinked in #Guix:
https://git.savannah.gnu.org/cgit/guix.git/commit/?h=core-updates&id=df93fc21a48047988b032ead90b0869491c834c8
In essence, mrustc (a Rust compiler in C++) is now used to build Rust 1.29, instead of 1.19 as was the case before:
https://guix.gnu.org/en/blog/2018/bootstrapping-rust/
