pg_basebackup --create-slot-if-not-exists?

Currently, pg_basebackup has
--create-slot option to create slot if not already exists or
--slot to use existing slot

Which means it needs knowledge on if the slot with the given name already
exists or not before invoking the command. If pg_basebackup --create-slot
<> command fails for some reason after creating the slot. Re-triggering the
same command fails with ERROR slot already exists. Either then need to
delete the slot and retrigger Or need to add a check before retriggering
the command to check if the slot exists and based on the same alter the
command to avoid passing --create-slot option. This poses
inconvenience while automating on top of pg_basebackup. As checking for
slot presence before invoking pg_basebackup unnecessarily involves issuing
separate SQL commands. Would be really helpful for such scenarios if
similar to CREATE TABLE, pg_basebackup can have IF NOT EXISTS kind of
semantic. (Seems the limitation most likely is coming from CREATE
REPLICATION SLOT protocol itself), Thoughts?

--
*Ashwin Agrawal (VMware)*