Heroku生产环境升级至heroku-22后Rails部署报fiber加载错误

TLDR; 我在Heroku上运行一个Rails应用，搭建了staging（预发布）和production（生产）环境组成的流水线。由于heroku-18堆栈已终止支持（EOL），正在将应用升级至heroku-22。预发布环境升级正常，但生产环境启动时出现错误：Unable to load application: LoadError: cannot load such file -- fiber

应用进程 #

• web.1：运行Rails的Puma Web服务器
• worker.1：运行Sidekiq的工作进程

web.1 崩溃日志 #

heroku[web.1]: Starting process with command `bundle exec puma -p 11167`
app[web.1]: [2] Puma starting in cluster mode...
app[web.1]: [2] * Puma version: 6.2.2 (ruby 3.2.2-p53) ("Speaking of Now")
app[web.1]: [2] *  Min threads: 5
app[web.1]: [2] *  Max threads: 5
app[web.1]: [2] *  Environment: production
app[web.1]: [2] *   Master PID: 2
app[web.1]: [2] *      Workers: 2
app[web.1]: [2] *     Restarts: (✔) hot (✖) phased
app[web.1]: [2] * Preloading application
app[web.1]: [2] ! Unable to load application: LoadError: cannot load such file -- fiber
app[web.1]: bundler: failed to load command: puma (/app/vendor/bundle/ruby/3.2.0/bin/puma)
app[web.1]: <internal:/app/vendor/ruby-3.2.2/lib/ruby/3.2.0/rubygems/core_ext/kernel_require.rb>:37:in `require': cannot load such file -- fiber (LoadError)
app[web.1]: from <internal:/app/vendor/ruby-3.2.2/lib/ruby/3.2.0/rubygems/core_ext/kernel_require.rb>:37:in `require'
app[web.1]: from /app/vendor/bundle/ruby/3.2.0/gems/zeitwerk-2.6.8/lib/zeitwerk/kernel.rb:38:in `require'
app[web.1]: from /app/vendor/bundle/ruby/3.2.0/gems/actionview-7.0.4.3/lib/action_view/renderer/streaming_template_renderer.rb:3:in `<top (required)>'
...

worker.1 崩溃日志 #

heroku[worker.1]: Starting process with command `bundle exec sidekiq`
heroku[worker.1]: State changed from starting to up
app[worker.1]: 2 TID-398 INFO: Booting Sidekiq 4.0.2 with redis options {:url=>"REDACTED", :ssl_params=>{:verify_mode=>0}}
app[worker.1]: bundler: failed to load command: sidekiq (/app/vendor/bundle/ruby/3.2.0/bin/sidekiq)
app[worker.1]: <internal:/app/vendor/ruby-3.2.2/lib/ruby/3.2.0/rubygems/core_ext/kernel_require.rb>:37:in `require': cannot load such file -- fiber (LoadError)
app[worker.1]: from <internal:/app/vendor/ruby-3.2.2/lib/ruby/3.2.0/rubygems/core_ext/kernel_require.rb>:37:in `require'
app[worker.1]: from /app/vendor/bundle/ruby/3.2.0/gems/zeitwerk-2.6.8/lib/zeitwerk/kernel.rb:38:in `require'
app[worker.1]: from /app/vendor/bundle/ruby/3.2.0/gems/actionview-7.0.4.3/lib/action_view/renderer/streaming_template_renderer.rb:3:in `<top (required)>'
...

环境详情 #

• ruby 3.2.2
• rails 7.0.4.3
• puma 6.2.2
• sidekiq 4.0.2（暂未升级，不影响web.1启动）
• 预发布与生产环境高度相似，仅生产环境多了newrelic_rpm依赖（该依赖未出现在崩溃调用栈中），资源配置几乎一致。

已尝试的解决方法（均失败后回滚） #

• 通过Heroku流水线功能将预发布应用晋升至生产环境
• 用CLI升级生产环境堆栈后手动部署
• 联系Heroku客服
• 设置环境变量HEROKU_DEBUG_RAILS_RUNNER=1，未获取到额外日志信息
• 部署失败后重启dynos
• 将dynos缩容至0后重新部署再扩容

内容的提问来源于stack exchange，提问作者Antón Morant