// Make sure that we cannot pass by argument a `&` that got already invalidated. fn foo(_: &i32) {} fn main() { let x = &mut 42; let xraw = x as *mut _; let xref = unsafe { &*xraw }; unsafe { *xraw = 42 }; // unfreeze foo(xref); //~ ERROR: /reborrow .* tag does not exist in the borrow stack/ }