Regression test PANICs with master-standby setup on same machine

Hello hackers,

With a master-standby setup configured on the same machine, I'm
getting a panic in tablespace test while running make installcheck.

1. CREATE TABLESPACE regress_tblspacewith LOCATION 'blah';
2. DROP TABLESPACE regress_tblspacewith;
3. CREATE TABLESPACE regress_tblspace LOCATION 'blah';
-- do some operations in this tablespace
4. DROP TABLESPACE regress_tblspace;

The master panics at the last statement when standby has completed
applying the WAL up to step 2 but hasn't started step 3.
PANIC:  could not fsync file
"pg_tblspc/16387/PG_12_201904072/16384/16446": No such file or
directory

The reason is both the tablespace points to the same location. When
master tries to delete the new tablespace (and requests a checkpoint),
the corresponding folder is already deleted by the standby while
applying WAL to delete the old tablespace. I'm able to reproduce the
issue with the attached script.

sh standby-server-setup.sh
make installcheck

I accept that configuring master-standby on the same machine for this
test is not okay. But, can we avoid the PANIC somehow? Or, is this
intentional and I should not include testtablespace in this case?

-- 
Thanks & Regards,
Kuntal Ghosh
EnterpriseDB: http://www.enterprisedb.com