Ruby版本升级遭遇Asset Pipeline配置错误求助

正在将Ruby版本从2.7.6升级至3.2.2，应用基于Rails 6.1.3 + Webpacker 6.0.0，暂计划后续升级Rails时再替换已弃用的Webpacker，当前遇到两处配置问题：

现有配置文件 #

app/assets/config/manifest.js内容：

//= link_tree ../images
//= link_directory ../javascripts .js
//= link_directory ../stylesheets .css
//= link_tree ../builds

报错1：测试用例执行失败 #

Failure/Error: <%= stylesheet_pack_tag 'application', media: 'all', 'data-turbo-track': 'reload' %>

ActionView::Template::Error:
  Webpacker can't find application.css in /Users/.../public/packs-test/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-test/js/application-5019ada8c79f4945bc85.js",
    "application.js.map": "/packs-test/js/application-5019ada8c79f4945bc85.js.map",
    "entrypoints": {
      "application": {
        "js": [
          "/packs-test/js/application-5019ada8c79f4945bc85.js"
        ],
        "js.map": [
          "/packs-test/js/application-5019ada8c79f4945bc85.js.map"
        ]
      }
    },
    "vendors~actioncable.js": "/packs-test/js/vendors~actioncable-111339b91a6898730a91.chunk.js",
    "vendors~actioncable.js.map": "/packs-test/js/vendors~actioncable-111339b91a6898730a91.chunk.js.map"
  }

报错2：资产预编译失败 #

Sprockets::DoubleLinkError: Multiple files with the same output path cannot be linked ("tailwind.css")
In "/Users/.../app/assets/config/manifest.js" these files were linked:
  - /Users/.../app/assets/stylesheets/tailwind.css
  - /Users/.../app/assets/builds/tailwind.css

1. 修复stylesheet_pack_tag找不到application.css的问题 #

Webpacker 6默认将CSS嵌入到JavaScript文件中，不再单独输出.css文件，因此manifest里不会生成application.css条目。

可选修复方式：

• 方式1：改用javascript_pack_tag加载：模板中替换stylesheet_pack_tag为javascript_pack_tag，它会自动处理嵌入的CSS：

  <%= javascript_pack_tag 'application', media: 'all', 'data-turbo-track': 'reload' %>
  

• 方式2：重新启用CSS提取：修改config/webpack/environment.js，配置CSS提取插件，确保Webpack单独输出CSS文件。示例配置：

  const { environment } = require('@rails/webpacker')
  const MiniCssExtractPlugin = require('mini-css-extract-plugin')
  
  environment.plugins.append('MiniCssExtractPlugin', new MiniCssExtractPlugin({
    filename: '[name].[contenthash].css'
  }))
  
  module.exports = environment
  

  同时确保config/webpacker.yml中对应环境的extract_css设置为true。

2. 修复Sprockets::DoubleLinkError重复链接问题 #

问题源于manifest.js同时链接了app/assets/stylesheets和app/assets/builds目录，而tailwind.css同时存在于这两个目录（原文件在stylesheets，Webpack编译后输出到builds），导致Sprockets检测到重复输出路径。

修复方式：修改app/assets/config/manifest.js，移除重复的链接规则。根据你的资产处理逻辑二选一：

• 如果Webpack负责编译所有CSS（包括tailwind），则移除stylesheets目录的链接：

  //= link_tree ../images
  //= link_directory ../javascripts .js
  //= link_tree ../builds
  

• 如果Sprockets负责处理stylesheets，限制builds目录只链接JS文件：

  //= link_tree ../images
  //= link_directory ../javascripts .js
  //= link_directory ../stylesheets .css
  //= link_tree ../builds .js
  

内容的提问来源于stack exchange，提问作者dxpo