{
  programs.borgmatic = {
    enable = true;
    backups = {
      main = {
        location = {
          repositories = [ "/mnt/disk1" ];
        };
      };
    };
  };

  test.asserts.assertions.expected = [
    ''
      Borgmatic backup configuration "main" must specify one of 'location.sourceDirectories' or 'location.patterns'.
    ''
  ];
}
