Minimizing Rust Binary Size

Another post for size constraint coding in Rust:<p><a href="https:&#x2F;&#x2F;www.codeslow.com&#x2F;2020&#x2F;01&#x2F;writing-4k-intro-in-rust.html" rel="nofollow">https:&#x2F;&#x2F;www.codeslow.com&#x2F;2020&#x2F;01&#x2F;writing-4k-intro-in-rust.ht...</a>

I am surprised that dynamically linking to Rust libstd and other common libraries is not mentioned. Rust produces (as far as Rust code is concerned, not sure about libc if used) fully static binaries by default, right?

&gt;<i>Cargo defaults its optimization level to 3 for release builds, which optimizes the binary for speed. To instruct Cargo to optimize for minimal binary size, use the z optimization level in Cargo.toml</i><p>In what scenarios is optimizing for binary size preferred over optimizing for speed?

What about `RUSTC_FLAGS=-Z opt=-Os` (this won&#x27;t work, I&#x27;m sure -- it is a total mishmash of things I&#x27;ve seen before but -Os is the relevant part). building your executable, your dependencies and&#x2F;or libstd w&#x2F;-Os could really pay off -- especially if you already have LTO enabled.

Not all of these should be used except when striving for absolute minimal sizes.

Sadly there is not before after result example.

I haven&#x27;t been following Rust&#x27;s development much lately, but I&#x27;m interested in understanding what&#x27;s the state of ABI stability...