error: Undefined Behavior: Data race detected between Write on thread `main` and Write on thread `` at ALLOC --> $DIR/fence_after_load.rs:LL:CC | LL | unsafe { V = 2 } | ^^^^^ Data race detected between Write on thread `main` and Write on thread `` at ALLOC | = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information = note: inside `main` at $DIR/fence_after_load.rs:LL:CC note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace error: aborting due to previous error