sungazer just failed with
pg_recvlogical exited with code '256', stdout '' and stderr 'pg_recvlogical: could not send replication command "START_REPLICATION SLOT "test_slot" LOGICAL 0/0 ("include-xids" '0', "skip-empty-xacts" '1')": ERROR: replication slot "test_slot" is active for PID 8913148
pg_recvlogical: disconnected
' at /home/nm/farm/gcc64/HEAD/pgsql.build/src/test/recovery/../../../src/test/perl/PostgresNode.pm line 1657.
https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=sungazer&dt=2017-08-24%2015%3A16%3A10
Looks like we're still not there on preventing replication startup
race conditions.
regards, tom lane