I just upgraded my Ubuntu to the new version with Rust written Coreutils - this is insane
% size /usr/bin/ls
text data bss dec hex filename
10086795 731540 2104 10820439 a51b57 /usr/bin/ls
% ls -sh /usr/lib/cargo/bin/coreutils/ls
11M /usr/lib/cargo/bin/coreutils/ls
% du -sh /usr/bin
1.5G /usr/bin
The entire rust coreutils package, as installed, is 12 MB https://packages.ubuntu.com/questing/rust-coreutils Which is nearly double the gnu coreutils package but still a complete nothing burger: https://packages.ubuntu.com/questing/gnu-coreutils
I think what's happening here is that they've all been compiled into one binary, and then that one binary hardlinked to a variety of names like /usr/bin/ls. Since they all show as having the same inode and the same size.
The other 1.5G of your 1.5G /usr/bin is unrelated to rust coreutils.