anchor.diff:        # Modify the state of the databases
         
         $testtarget1->mustSucceed("echo \"insert into test values ('Bye world');\" | mysql --user=root --password=verysecret -N testdb");
  -      $testtarget1->mustSucceed("echo \"insert into test values ('Bye world');\" | psql --file - testdb");
  +      $testtarget1->mustSucceed("echo \"insert into test values ('Bye world');\" | su postgres -s /bin/sh -c 'psql --file - testdb'");
         
         # Remove all the remote snapshots and check if both the Disnix and NixOS
         # state dir have no snapshots
  
positive.code:           print "MySQL does not contain: Bye world!\n";
        }
        
        $result = $testtarget1->mustSucceed("echo 'select * from test' | psql --file - testdb");
        
        if($result =~ /Bye world/) {
            die "PostgreSQL table should not contain: Bye world!\n";
  
negative.code:             package = pkgs.postgresql;
            };
            
            environment.systemPackages = [ (builtins.storePath ${disnix}) ];
          };
        }
      '';
  