pg_basebackup exit codes

Hi,

I was unpleasantly surprised to see that pg_basebackup will return a zero (Success) exit code even when it has actually failed like below:

pg_basebackup: could not write to compressed file "/var/lib/pgsql/10/inst1/backup/cust-pg02_inst1_Fri_20190816/base.tar.gz": No space left on device
pg_basebackup: removing data directory "/var/lib/pgsql/10/inst1/backup/cust-pg02_inst1_Fri_20190816"

A reliable exit code is of great importance in backup scripts using a statement like below:

pg_basebackup -D ${backup_dest} -Ft -z 2>&1 | tee -a ${log_file}; rv=$?
[ $rv -eq 0 ] || error "pg_basebackup failed with rcode $rv; also see ${log_file}"

Pg_basebackup version: (PostgreSQL) 10.10

Anybody else encountering this problem?

Regards, John