[vvanders]

If you looked at the link you included you'd see why the Rust version is larger, because they include the static library.

There's nothing about Rust that intrinsically makes it larger than C.

[bjornha]

You would need a basic standard library built with the binary when building for xtensa (esp) aswell. So yes, the size of the core parts of the stdlib between c and rust definitely do play a role.