error: Undefined Behavior: not granting access to tag because incompatible item is protected: [Unique for (call ID)] --> $DIR/illegal_write6.rs:LL:CC | LL | unsafe { *y = 2; } | ^^^^^^ not granting access to tag because incompatible item is protected: [Unique for (call ID)] | = help: this indicates a potential bug in the program: it performed an invalid operation, but the Stacked Borrows rules it violated are still experimental = help: see https://github.com/rust-lang/unsafe-code-guidelines/blob/master/wip/stacked-borrows.md for further information help: tag was most recently created at offsets [0x0..0x4] --> $DIR/illegal_write6.rs:LL:CC | LL | let p = x as *mut u32; | ^ help: was protected due to a tag which was created here --> $DIR/illegal_write6.rs:LL:CC | LL | foo(x, p); | ^ help: this protector is live for this call --> $DIR/illegal_write6.rs:LL:CC | LL | / fn foo(a: &mut u32, y: *mut u32) -> u32 { LL | | *a = 1; LL | | let _b = &*a; LL | | unsafe { *y = 2; } LL | | return *a; LL | | } | |_^ = note: inside `foo` at $DIR/illegal_write6.rs:LL:CC note: inside `main` at $DIR/illegal_write6.rs:LL:CC --> $DIR/illegal_write6.rs:LL:CC | LL | foo(x, p); | ^^^^^^^^^ note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace error: aborting due to previous error