pg_dump INDEX ATTACH versus --clean option

I noticed that pg_dump --clean does not work with partitioned
indexes. Given for instance

create schema s1;
create table s1.at1 (f1 int, f2 int, primary key(f1,f2)) partition by list(f1);
create table s1.at11 partition of s1.at1 for values in(11);
create table s1.at12 partition of s1.at1 for values in(12);

then "pg_dump -n s1 -c mydb >mydb.dump" will emit

ALTER TABLE ONLY s1.at12 DROP CONSTRAINT at12_pkey;
ALTER TABLE ONLY s1.at11 DROP CONSTRAINT at11_pkey;
ALTER TABLE ONLY s1.at1 DROP CONSTRAINT at1_pkey;
DROP TABLE s1.at12;
DROP TABLE s1.at11;
DROP TABLE s1.at1;
DROP SCHEMA s1;
... then create the objects ...

which naturally results in

psql:mydb.dump:19: ERROR: cannot drop inherited constraint "at12_pkey" of relation "at12"
psql:mydb.dump:20: ERROR: cannot drop inherited constraint "at11_pkey" of relation "at11"
ALTER TABLE
DROP TABLE
DROP TABLE
DROP TABLE
DROP SCHEMA

That's not really okay, since it'd break a single-transaction
restore.

Since there's no ALTER INDEX DETACH PARTITION, it's not entirely
clear what to do about this. We could possibly not emit any
dropStmt for partition child indexes, but that seems very likely
to cause problems for partial-restore scenarios.

regards, tom lane