Grouping function error when grouping sets are not specified

hive> select grouping(c1), lead(c2) over(partition by grouping(c1)) from e011_01 group by c1, c2;
FAILED: SemanticException Failed to breakup Windowing invocations into Groups. At least 1 group must only depend on input columns. Also check for circular dependencies.
Underlying error: org.apache.hadoop.hive.ql.parse.SemanticException: Line 1:48 Arguments length mismatch 'c1': grouping() requires 2 argument, got 1