Panic when condvar will never be notified

Author: surban

library/std/src/sys/sync/condvar/no_threads.rs

@@ -29,9 +29,7 @@ impl Condvar {
     pub unsafe fn wait(&self, _mutex: &Mutex) {
         let mut value = self.value.borrow_mut();
         if *value == 0 {
-            // Since the target does not have threads,
-            // no notification can ever arrive.
-            loop {}
+            panic!("condvar will never be notified");
         } else {
             *value -= 1;
         }