Because rebuilding everything all the bloody time is expensive. Virtually every Linux distribution and BSD share this concern. We've all complained about it to

Because rebuilding everything all the bloody time is expensive. Virtually every Linux distribution and BSD share this concern. We've all complained about it to Rust upstream, but they don't care. To them, it's cheap to rebuild every Rust project every time the compiler is updated or the standard library needs a fix. See for yourself: https://github.com/rust-lang/rfcs/issues/600 https://github.com/rust-lang/rfcs/issues/600 What's worse is that a lot of people are forgetting why we do it this way in the first place. While part of it was about saving disk space, the major reason we do this is for being able to fix things in a cheap way and have wide-ranging impact. Without this, things like security fixes to zlib, libvpx, or other important libraries would require finding all their reverse dependencies, patching them, and rebuilding them to incorporate the fixes. It's incredibly important, but because nobody cares in Rust and Mozilla, we're all doomed...