Anonymous blocks are not allowed unless they are part of a mixin. — Что за ошибка?

Question

[Skrolea]

Как вставить один миксин в другой? Сейчас ругается на include ../buttons/buttons

mixin article-card(spec)
include ../buttons/buttons
  - spec = spec || {}
  - spec.__class = spec.__class || 'article-card'

  div(class=spec.__class)&attributes(attributes)
   .article-card__img
    img(src="images/news/12.png")
   .article-card__body
     .article-card__date
       p 20.11.2016
     .article-card__content              
      .article-card__title
         h3 Заголовок
      .article-card__description
         p Описание
     .article-card__buttons
        i.material-icons.article-icon share        
        #[+buttons({class: 'button',text:'Далее'})]

Почему он Anonymous blocks?

Answer 1

[Олег]

include ../buttons/buttons

mixin article-card()
    div&attributes(attributes)
        +buttons