anchor.diff:              package = pkgs.postgresql;
             };
             
  -          environment.systemPackages = [ ${disnix} ];
  +          environment.systemPackages = [ (builtins.storePath ${disnix}) ];
           };
         
           testtarget2 = {pkgs, ...}:
  
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:       # 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');\" | 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
  