Fwiw, in something like hello world, most of the size is just the rust standard library that's statically linked in. Unused parts don't get removed as it is precompiled (unless there's some linker magic I am unaware of). A C program dynamically links to the system's libc so it doesn't pay the same cost.

Before a few days ago I would have told you that the smallest binary rustc has ever produced is 137 bytes, but I told that to someone recently and they tried to reproduce and got it down to 135.

The default settings don’t optimize for size, because for most people, this doesn’t matter. But if you want to, you can.

> And as I pointed out in a comment below, your release binary of 440k is still larger than necessary by a factor 2000x or so.

This is such a silly argument because nobody is optimizing compilers and standard libraries for Hello World utilities.

It's also ridiculous to compare debug builds in rust against release builds for something else.

If you want a minimum sized Hello World app in rust then you'd use nostd, use a no-op panic handler, and make the syscalls manually.

> The rust compiler package takes up 240mb on my machine. That means rust is about 10x larger than a fully functional desktop OS from 30 years ago.

Fortunately for all of us, storage costs and bandwidth prices have improved by multiple orders of magnitude since then.

Which is why we don't care. The added benefits of modern software are great.

You're welcome to go back and use a 30 year old desktop OS if you'd like, though.

rustc --version && rustc main.rs && ls -alh main

rustc 1.85.0 (4d91de4e4 2025-02-17) -rwxr-xr-x 1 user user 436K 21 Feb 17:17 main

What's your output for `rustup default`?

Also, what's your output when you follow min-sized-rust?