#Rustlang 1.67 added extra optimizations of struct layouts. This might break code that relied on the "don't rely on this" layout of Rust structs without `#[repr(C)]`.

If you want to ensure your code doesn't rely on undocumented struct layout, there's an nightly flag for that: github.com/rust-lang/rust/issu…

RUSTFLAGS="-Z randomize-layout" cargo +nightly test

Tracking issue for `-Z randomize-layout` · Issue #106764 · rust-lang/rust

This is a tracking issue for the unstable rustc flag -Zrandomize-layout. (rust-lang/compiler-team#457) About tracking issues Tracking issues are used to record the overall progress of implementatio...

^GitHub