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(dot)ruiz(at)harmonie-mutuelle(dot)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.

Thanks for your help/answers.

Sébastien.