For some reason the developers of the Ubuntu Linux distribution have decided to replace all the GNU core utilities, which are written in C, with replacements written in Rust. The problem? For an unfathomable reason they are rushing the publication of these new replacements even before they are ready. Indeed, the GNU core utils have a big bunch of automated tests that are run on them every time before a new version release. The Rust replacements developed by the Ubuntu developers fail hundreds of these tests. Some of the replacements fail all the tests for that particular utility. On top of that, many of the replacements written in Rust are significantly slower than the originals that are written in C. Some of the utilities run a whopping 17 times slower than the original C counterpart. Not 17% slower; 17 times slower! Other utilities (such as sort ) can't handle files even nearly as large as the original C version, failing with files that the C version has no problems ...