Query fails with "A conflict is detected. This is unexpected."

	@Test
	public void test() throws Exception {
		tableEnv.executeSql("create table src(key string,val string)");
		tableEnv.executeSql("SELECT sum(char_length(src5.src1_value)) FROM " +
				"(SELECT src3.*, src4.val as src4_value, src4.key as src4_key FROM src src4 JOIN " +
				"(SELECT src2.*, src1.key as src1_key, src1.val as src1_value FROM src src1 JOIN src src2 ON src1.key = src2.key) src3 " +
				"ON src3.src1_key = src4.key) src5").collect();
	}