Could not find one or more icon(s)

Question

vue项目中引用font-awesome报错 Could not find one or more icon(s) {prefix: "fas", iconName: "lock"} {}
这里引用了两个图标,user图标可以正常显示，但是lock图标无法显示提示错误 Could not find one or more icon(s) {prefix: "fas", iconName: "lock"} {}，为什么会一个显示一个不显示，应该怎么改？

<font-awesome-icon :icon="['fas', 'user']" slot="prepend"></font-awesome-icon>
<font-awesome-icon :icon="['fas', 'lock']" slot="prepend"></font-awesome-icon>

main.js中引用图标的方式：

import {library} from '@fortawesome/fontawesome-svg-core'

import {faUser} from '@fortawesome/free-solid-svg-icons'

import {far} from '@fortawesome/free-regular-svg-icons'
import {fab} from '@fortawesome/free-brands-svg-icons'
import {FontAwesomeIcon, FontAwesomeLayers, FontAwesomeLayersText}
  from '@fortawesome/vue-fontawesome'

library.add(faUser, far, fab)
Vue.component('font-awesome-icon', FontAwesomeIcon)
Vue.component('font-awesome-layers', FontAwesomeLayers)
Vue.component('font-awesome-layers-text', FontAwesomeLayersText)

Answer 1

下文中粗体部分是修改后的，亲测可用，faUser改为fas其他引用方式均未改变。
import {fas} from '@fortawesome/free-solid-svg-icons'
library.add(fas, far, fab)

完整引用

import {library} from '@fortawesome/fontawesome-svg-core'

import {fas} from '@fortawesome/free-solid-svg-icons'

import {far} from '@fortawesome/free-regular-svg-icons'
import {fab} from '@fortawesome/free-brands-svg-icons'
import {FontAwesomeIcon, FontAwesomeLayers, FontAwesomeLayersText}
  from '@fortawesome/vue-fontawesome'

library.add(fas, far, fab)
Vue.component('font-awesome-icon', FontAwesomeIcon)
Vue.component('font-awesome-layers', FontAwesomeLayers)
Vue.component('font-awesome-layers-text', FontAwesomeLayersText)