## 事象
`nuxt`コマンドを実行すると以下のエラーが表示される。
```
WARN Though the "loose" option was set to "false" in your @babel/preset-env config, it will not be used for @babel/plugin-proposal-private-property-in-object since the "loose" mode option was set to "true" for @babel/plugi
n-proposal-private-methods.
The "loose" option must be the same for @babel/plugin-proposal-class-properties, @babel/plugin-proposal-private-methods and @babel/plugin-proposal-private-property-in-object (when they are enabled): you can silence this warn
ing by explicitly adding
["@babel/plugin-proposal-private-property-in-object", { "loose": true }]
to the "plugins" section of your Babel config.
```
## 原因
ちゃんと調べていない。
## 解決方法
`nuxt.config.js`に設定を追加する。
```diff:nuxt.config.js
build: {
babel: {
+ plugins: [
+ ['@babel/plugin-proposal-private-property-in-object', { loose: true }],
+ ],
}
}
```
## 参考
<div class="link-card">
<div class="link-card-header">
<img src="https://github.githubassets.com/favicons/favicon.svg" class="link-card-site-icon"/>
<span class="link-card-site-name">GitHub</span>
</div>
<div class="link-card-body">
<div class="link-card-content">
<div>
<p class="link-card-title">Babel "loose" option error spamming in console on fresh project · Issue #9224 · nuxt/nuxt.js</p>
</div>
<div class="link-card-description">
Versions nuxt: v2.15.4 node: v14 Reproduction Just make a new project on CodeSandbox and you'll see the error. Here is one I just made: https://codesandbox.io/s/serene-thunder-yl6rq Steps to re...
</div>
</div>
<img src="https://opengraph.githubassets.com/1eb54650fae4713bb355416589ef2fc4abbc207d2db7a610c4fe4c72ff93e67f/nuxt/nuxt.js/issues/9224" class="link-card-image"/>
</div>
<a href="https://github.com/nuxt/nuxt.js/issues/9224#issuecomment-893289291"></a>
</div>