Ubuntu 25.10’s transition to using Rust Coreutils in place of GNU Coreutils has uncovered a few performance issues so far with the Rust version being slower than the C-based GNU Coreutils. Fortunately there still are a few weeks to go until Ubuntu 25.10 releases as stable and upstream developers are working to address these performance gaps.
Wasn’t rust suppose to both more performant and more memory safe than it’s C counterparts?
Rust and C are the same “tier” of performance, but GNU coreutils has the benefit of several decades of development and optimization that the Rust one needs to catch up with.