// should find the bug even without these, but gets masked by optimizations
// compile-flags: -Zmiri-disable-validation -Zmiri-disable-stacked-borrows -Zmir-opt-level=0

#[repr(align(256))]
#[derive(Debug)]
struct MuchAlign;

fn main() {
    let buf = [0u32; 256];
    // `buf` is sufficiently aligned for `layout.align` on a `dyn Debug`, but not
    // for the actual alignment required by `MuchAlign`.
    // We craft a wide reference `&dyn Debug` with the vtable for `MuchAlign`. That should be UB,
    // as the reference is not aligned to its dynamic alignment requirements.
    let mut ptr = &MuchAlign as &dyn std::fmt::Debug;
    // Overwrite the data part of `ptr` so it points to `buf`.
    unsafe { (&mut ptr as *mut _ as *mut *const u8).write(&buf as *const _ as *const u8); }
    // Re-borrow that. This should be UB.
    let _ptr = &*ptr; //~ ERROR accessing memory with alignment 4, but alignment 256 is required
}