エラーになった過程

vueをrails6に導入して、vuetifyを追加。→試しにvuetifyのパーツをコピペ。→うまく機能しているかブラウザで確かめるため、rails s→コンパイル時にエラー発生。

#エラー内容

ActionView::Template::Error (Webpacker can't find hello_vue in /usr/src/myapp/public/packs/manifest.json. Possible causes:
1. You want to set webpacker.yml value of compile to true for your environment
   unless you are using the `webpack -w` or the webpack-dev-server.
2. webpack has not yet re-run to reflect updates.
3. You have misconfigured Webpacker's config/webpacker.yml file.
4. Your webpack configuration is not creating a manifest.
Your manifest contains:
{
  "application.js": "/packs/js/application-9afcbb5693aa87623e69.js",
  "application.js.map": "/packs/js/application-9afcbb5693aa87623e69.js.map",
  "components/user.js": "/packs/js/components/user-156f569cb5c8b04ee2e1.js",
  "components/user.js.map": "/packs/js/components/user-156f569cb5c8b04ee2e1.js.map",
  "entrypoints": {
    "application": {
      "js": [
        "/packs/js/application-9afcbb5693aa87623e69.js"
      ],
      "js.map": [
        "/packs/js/application-9afcbb5693aa87623e69.js.map"
      ]
    },
    "components/user": {
      "js": [
        "/packs/js/components/user-156f569cb5c8b04ee2e1.js"
      ],
      "js.map": [
        "/packs/js/components/user-156f569cb5c8b04ee2e1.js.map"
      ]
    },
    "main": {
      "js": [
        "/packs/js/main-f6918c73db91592ebf7f.js"
      ],
      "js.map": [
        "/packs/js/main-f6918c73db91592ebf7f.js.map"
      ]
    }
  },
  "main.js": "/packs/js/main-f6918c73db91592ebf7f.js",
  "main.js.map": "/packs/js/main-f6918c73db91592ebf7f.js.map"
}
):
    11: 
    12:   <body>
    13:     <%= yield %>
    14:     <%= javascript_pack_tag 'hello_vue' %>
    15:   </body>
    16: </html>
  
app/views/layouts/application.html.erb:14
^C- Gracefully stopping, waiting for requests to finish
=== puma shutdown: 2020-11-12 02:56:13 +0000 ===
- Goodbye!

ここにも書いてあるが、→https://github.com/rails/webpacker#vue
下のコマンドを上から実行していくと、エラーが解決しました。

./bin/rails webpacker:install
./bin/rails webpacker:install:vue
bin/webpack