rustc/tests/ui/macros/assert-ne-macro-msg.rs

// run-fail
// error-pattern:assertion `left != right` failed: 1 + 1 definitely should not be 2
// error-pattern:  left: 2
// error-pattern: right: 2
// ignore-emscripten no processes

fn main() {
    assert_ne!(1 + 1, 2, "1 + 1 definitely should not be 2");
}