Inserting into an im::OrdSet (for example by collecting an iterator into one) can violate Rust's aliasing rules: Miri reports a stacked borrows violation in sized chunks::Chunk::force copy(), which is called during insertion, where a shared borrow is invalidated by a unique borrow before the read through it completes. This is undefined behavior, reachable from safe code.

No fixed version is available, as the crate is unmaintained; its GitHub repository was archived by the owner on 2026-05-03.