Re: BUG #16003: pg_basebackup failed with error : directory "xxxxxxx"exists but is not empty

The following bug has been logged on the website:

Bug reference:      16003
Logged by:          sebastien ruiz
Email address:      sebastien.ruiz@harmonie-mutuelle.fr
PostgreSQL version: 11.4
Operating system:   Red Hat Enterprise Linux Server release 7.6
Description:       

hello,
(sorry i'm french)

We have a problem when using pg_basebackup.
We tried to rebuild a slave (master/slave with streaming replication) using
pg_basebackup like this :
(executed on the slave server of course)
pg_basebackup -D /pgbd/IPMUTB6/admin  -P -h PGSMUTB61 -p 5432 -U postgres
-X stream -v  --waldir=/pgxlog/IPMUTB6/wal

But it failed :
pg_basebackup: initiating base backup, waiting for checkpoint to complete
pg_basebackup: checkpoint completed
pg_basebackup: write-ahead log start point: 0/17000028 on timeline 5
pg_basebackup: directory "/pgbd/IPMUTB6/data/dpaafb1_data" exists but is not
empty
pg_basebackup: removing data directory "/pgbd/IPMUTB6/admin"
pg_basebackup: removing WAL directory "/pgxlog/IPMUTB6/wal"
pg_basebackup: changes to tablespace directories will not be undone

in fact it failed because we have an architecture of tablespace who is not
compatible with the pg_basebackup tests/controls.

This is how our tablespace architecture looks like :
postgres=# \db
                               List of tablespaces
         Name          |  Owner   |                   Location
-----------------------+----------+-----------------------------------------------
 aafb1_dpaafb1_data    | aafb1    |
/pgbd/IPMUTB6/data/dpaafb1_data/aafb1_data
 aafb1_dpaafb1_idx     | aafb1    |
/pgbd/IPMUTB6/idx/dpaafb1_idx/aafb1_idx
 dpaafb1_data          | postgres | /pgbd/IPMUTB6/data/dpaafb1_data
 dpaafb1_idx           | postgres | /pgbd/IPMUTB6/idx/dpaafb1_idx
 dpccmb1_data          | postgres | /pgbd/IPMUTB6/data/dpccmb1_data
 dpccmb1_idx           | postgres | /pgbd/IPMUTB6/idx/dpccmb1_idx
 dptemb1_data          | postgres | /pgbd/IPMUTB6/data/dptemb1_data
 dptemb1_idx           | postgres | /pgbd/IPMUTB6/idx/dptemb1_idx
 pg_default            | postgres |
 pg_global             | postgres |
 tech_dpaafb1_data     | tech     |
/pgbd/IPMUTB6/data/dpaafb1_data/tech_data
 tech_dpaafb1_idx      | tech     | /pgbd/IPMUTB6/idx/dpaafb1_idx/tech_idx
 tech_dpccmb1_data     | tech     |
/pgbd/IPMUTB6/data/dpccmb1_data/tech_data
 tech_dpccmb1_idx      | tech     | /pgbd/IPMUTB6/idx/dpccmb1_idx/tech_idx
 tech_dptemb1_data     | tech     |
/pgbd/IPMUTB6/data/dptemb1_data/tech_data
 tech_dptemb1_idx      | tech     | /pgbd/IPMUTB6/idx/dptemb1_idx/tech_idx
 temp                  | postgres | /pgtemp/IPMUTB6/tmp
 tempob1_dptemb1_data  | tempob1  |
/pgbd/IPMUTB6/data/dptemb1_data/tempob1_data
 tempob1_dptemb1_idx   | tempob1  |
/pgbd/IPMUTB6/idx/dptemb1_idx/tempob1_idx
 webccmb1_dpccmb1_data | webccmb1 |
/pgbd/IPMUTB6/data/dpccmb1_data/webccmb1_data
 webccmb1_dpccmb1_idx  | webccmb1 |
/pgbd/IPMUTB6/idx/dpccmb1_idx/webccmb1_idx

In summary, we have tablespace directories into tablespace directories.

exemple :
/pgbd/IPMUTB6/data/dpaafb1_data/aafb1_data is inside the directory
/pgbd/IPMUTB6/data/dpaafb1_data

And this point is not compatible with pg_basebackup usage.

My question :
is it possible to make pg_basebackup compatible with this situation ?
I'm sure that many entreprise have this kind of architecture.
We can't use pg_basebackup  and it's really too bad for us.