Liker nas fotos

Implementei a função, porém quando vou dar like ele da erro dizendo que o login nao existe, segue o código:

class FotoInfo extends Component {

    constructor(props){
        super(props);

        this.state = {likers: this.props.foto.likers};
    }

    componentWillMount(){
        PubSub.subscribe('atualiza-liker', (topico, infoLiker) => {
            if(this.props.foto.id === infoLiker.fotoId){
                const possivelLiker = this.state.likers.find(liker => liker.login === infoLiker.liker.login);

                if(possivelLiker === undefined){
                    const novosLikers = this.state.likers.concat(infoLiker.likers);
                    this.setState({likers:novosLikers});
                }else{
                    const novosLikers = this.state.likers.filter(liker => liker.login !== infoLiker.liker.login);
                    this.setState({likers:novosLikers});
                }
            }
        });
    }

    render(){
        return (
            <div className="foto-in fo">
                <div className="foto-info-likes">
                    {
                        this.state.likers.map(liker => {
                            console.log(liker);
                            return (<Link key={liker.login} href={`/timeline/${liker.login}`}>{liker.login},</Link>)
                        })
                    }
                    curtiram
                </div>
                <p className="foto-info-legenda">
                    <a className="foto-info-autor">autor </a>
                    {this.props.foto.comentario}
                </p>         
                <ul className="foto-info-comentarios">
                    {
                        this.props.foto.comentarios.map(comentario => {
                            return (
                                <li className="comentario" key={comentario.id}>
                                    <Link to={`/timeline/${comentario.login}`} className="foto-info-autor">{comentario.login} </Link>
                                    {comentario.texto}
                                </li>
                            );
                        })
                    }
                </ul>
            </div>            
        );
    }
}

O que poderia ser?