Error "no previous SQL command" in !plan in !if

[julianhyde]

The following script gives an error:

select job, sum(sal) as sum_sal, deptno
from "scott".emp
where deptno = 10
group by deptno, job;
+-----------+---------+--------+
| JOB       | SUM_SAL | DEPTNO |
+-----------+---------+--------+
| CLERK     | 1300.00 |     10 |
| MANAGER   | 2450.00 |     10 |
| PRESIDENT | 5000.00 |     10 |
+-----------+---------+--------+
(3 rows)

!ok
!if (fixed.calcite794) {
EnumerableCalc(expr#0..2=[{inputs}], JOB=[$t0], SUM_SAL=[$t2], DEPTNO=[$t1])
  EnumerableAggregate(group=[{2, 7}], SUM_SAL=[SUM($5)])
    EnumerableCalc(expr#0..7=[{inputs}], expr#8=[CAST($t7):INTEGER], expr#9=[10], expr#10=[=($t8, $t9)], proj#0..7=[{exprs}], $condition=[$t10])
      EnumerableTableScan(table=[[scott, EMP]])
!plan
!}