Heroku Bundler版本更新移除已安装gem致应用部署编译失败

我有一个正常运行的ROR Heroku应用，平时定期上传代码变更。最近仅修改了少量CSS，没碰过Gemfile和Gemfile.lock，本地编译运行完全正常，但部署时Heroku自动把Bundler从2.3.10升级到2.3.25，导致编译失败。对比日志发现新版Bundler移除了mini_portile2 (2.6.1)，但有其他gem依赖这个包，而且它明明已经在Gemfile和Gemfile.lock里了。试过删除重新生成Gemfile.lock、升级mini_portile2版本，都没解决。

上次成功部署日志 #

-----> Using buildpack: heroku/ruby
-----> Ruby app detected
-----> Installing bundler 2.3.10
-----> Removing BUNDLED WITH version in the Gemfile.lock
-----> Compiling Ruby/Rails
-----> Using Ruby version: ruby-2.7.1
-----> Installing dependencies using bundler 2.3.10
       Running: BUNDLE_WITHOUT='development:test' BUNDLE_PATH=vendor/bundle BUNDLE_BIN=vendor/bundle/bin BUNDLE_DEPLOYMENT=1 bundle install -j4
       Using rake 13.0.6
       Using concurrent-ruby 1.1.9
       Using i18n 1.8.10
       Using minitest 5.14.4
       Using tzinfo 2.0.4
       Using zeitwerk 2.4.2
       Using activesupport 6.1.3.2
       Using builder 3.2.4
       Using erubi 1.10.0
       Using mini_portile2 2.6.1
       Using racc 1.5.2
       .....
       Bundle complete! 39 Gemfile dependencies, 132 gems now installed.
       Gems in the groups 'development' and 'test' were not installed.
       Bundled gems are installed into `./vendor/bundle`
       Bundle completed (0.88s)
       Cleaning up the bundler cache.
-----> Installing node-v16.13.1-linux-x64
-----> Installing yarn-v1.22.17
-----> Detecting rake tasks
-----> Preparing app for Rails asset pipeline
       Running: rake assets:precompile

本次失败部署日志 #

-----> Building on the Heroku-18 stack
remote: -----> Using buildpack: heroku/ruby
remote: -----> Ruby app detected
remote: -----> Installing bundler 2.3.25
remote: -----> Removing BUNDLED WITH version in the Gemfile.lock
remote: -----> Compiling Ruby/Rails
remote:
remote: ###### WARNING:
remote:
remote:        Your app was upgraded to bundler 2.3.25.
remote:        Previously you had a successful deploy with bundler 2.3.10.
remote:
remote:
remote: -----> Using Ruby version: ruby-2.7.1
remote: -----> Installing dependencies using bundler 2.3.25
remote:        Running: BUNDLE_WITHOUT='development:test' BUNDLE_PATH=vendor/bundle BUNDLE_BIN=vendor/bundle/bin BUNDLE_DEPLOYMENT=1 bundle install -j4
remote:        Using rake 13.0.6
remote:        Using concurrent-ruby 1.1.9
remote:        Using i18n 1.8.10
remote:        Using minitest 5.14.4
remote:        Using tzinfo 2.0.4
remote:        Using zeitwerk 2.4.2
remote:        Using activesupport 6.1.3.2
remote:        Using builder 3.2.4
remote:        Using erubi 1.10.0
remote:        Using racc 1.5.2
               .....
remote:        Bundle complete! 39 Gemfile dependencies, 131 gems now installed.
remote:        Gems in the groups 'development' and 'test' were not installed.
remote:        Bundled gems are installed into `./vendor/bundle`
remote:        Bundle completed (0.69s)
remote:        Cleaning up the bundler cache.
remote:        Removing bundler (2.3.10)
remote:        Removing mini_portile2 (2.6.1)
remote: -----> Installing node-v16.18.1-linux-x64
remote: -----> Installing yarn-v1.22.19
remote: -----> Detecting rake tasks
remote:
remote:  !
remote:  !     Could not detect rake tasks
remote:  !     ensure you can run `$ bundle exec rake -P` against your app
remote:  !     and using the production group of your Gemfile.
remote:  !     /tmp/build_5db96fd8/vendor/ruby-2.7.1/lib/ruby/2.7.0/bundler/spec_set.rb:86:in `block in materialize': Could not find mini_portile2-2.7.0 in any of the sources (Bundler::GemNotFound)

解决方案 #

1. 锁定Bundler版本 #

既然旧版本Bundler能正常部署，直接在项目里锁定版本避免Heroku自动升级：

• 本地运行：bundle lock --add-platform x86_64-linux（确保Gemfile.lock包含Linux平台依赖）
• 在项目根目录创建.bundle/config文件，写入：

  BUNDLED WITH:
    2.3.10
  

• 或者在Gemfile里显式指定：

  gem 'bundler', '2.3.10'
  

• 提交所有变更后重新部署。

2. 显式指定mini_portile2版本 #

错误提示找不到2.7.0版本，但你的依赖实际需要2.6.1，直接在Gemfile里强制指定：

• 添加：gem 'mini_portile2', '2.6.1'
• 运行bundle install更新Gemfile.lock
• 提交Gemfile和Gemfile.lock后重新部署。

3. 清理Heroku缓存 #

缓存可能导致依赖异常，部署前先清理：

heroku repo:purge_cache -a your-app-name

再推送代码重新部署。

内容的提问来源于stack exchange，提问作者Idb