XX000: ORDER/GROUP BY expression not found in list, with caggs

-- ORDER BY on the aggregate column of a DISTINCT grouped subquery over a
-- continuous aggregate errors out in the planner when the GROUP BY reordering
-- optimization for continuous aggregates is enabled (the default).

create table cloud_cover (observed_at timestamptz not null, cover_percent float);
select create_hypertable('cloud_cover', 'observed_at');

create materialized view daily_cloud_cover with (timescaledb.continuous) as
select time_bucket('1 day', observed_at) as day, max(cover_percent) as max_cover
from cloud_cover group by 1 with no data;

create table stations (region text);

-- baseline: with the reordering optimization disabled the query works
set timescaledb.enable_cagg_reorder_groupby = off;
select * from (
    select distinct s.region, max(c.max_cover) as peak
    from daily_cloud_cover c, stations s
    group by s.region) q
order by peak;

-- the same query with the default setting
reset timescaledb.enable_cagg_reorder_groupby;
select * from (
    select distinct s.region, max(c.max_cover) as peak
    from daily_cloud_cover c, stations s
    group by s.region) q
order by peak;  -- ERROR:  ORDER/GROUP BY expression not found in list