Use cerr instead of clog to make sure cout has been flushed before errors get displayed

src/main.cpp

@@ -93,7 +93,7 @@ int main(int argc, char* argv[]) {
                 }
             } else {
                 cout << "Compilation of " << result.first << " has failed with the following error:\n";
-                clog << result.second.value().what() << '\n';
+                cerr << result.second.value().what() << '\n';
             }
             return is_exception;
         })) {