Rails 7 Ruby 3.1 LoadError：无法加载此类文件--net/smtp

Question

我升级到 Rails 7 和 Ruby 3.1。 尝试使用rspec运行测试时，出现以下错误。 我该如何解决？

An error occurred while loading rails_helper.
Failure/Error: require File.expand_path('../config/environment', __dir__)

LoadError:
  cannot load such file -- net/smtp
# .../gems/bootsnap-1.9.3/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:34:in `require'
# .../gems/zeitwerk-2.5.2/lib/zeitwerk/kernel.rb:36:in `require'
# .../gems/mail-2.7.1/lib/mail.rb:9:in `<module:Mail>'
# .../gems/mail-2.7.1/lib/mail.rb:3:in `<main>'
# .../gems/bootsnap-1.9.3/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:23:in `require'
# .../gems/bootsnap-1.9.3/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:23:in `block in require_with_bootsnap_lfi'
# .../gems/bootsnap-1.9.3/lib/bootsnap/load_path_cache/loaded_features_index.rb:100:in `register'
# .../gems/bootsnap-1.9.3/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:22:in `require_with_bootsnap_lfi'
# .../gems/bootsnap-1.9.3/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:31:in `require'
# .../gems/zeitwerk-2.5.2/lib/zeitwerk/kernel.rb:36:in `require'
# .../bundler/gems/rails-6a0f6c4d70b1/actionmailbox/lib/action_mailbox/mail_ext.rb:3:in `<main>'
# .../gems/bootsnap-1.9.3/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:23:in `require'
# .../gems/bootsnap-1.9.3/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:23:in `block in require_with_bootsnap_lfi'
# .../gems/bootsnap-1.9.3/lib/bootsnap/load_path_cache/loaded_features_index.rb:100:in `register'
# .../gems/bootsnap-1.9.3/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:22:in `require_with_bootsnap_lfi'
# .../gems/bootsnap-1.9.3/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:31:in `require'
# .../gems/zeitwerk-2.5.2/lib/zeitwerk/kernel.rb:36:in `require'
# .../bundler/gems/rails-6a0f6c4d70b1/actionmailbox/lib/action_mailbox.rb:3:in `<main>'
# .../gems/bootsnap-1.9.3/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:23:in `require'
# .../gems/bootsnap-1.9.3/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:23:in `block in require_with_bootsnap_lfi'
# .../gems/bootsnap-1.9.3/lib/bootsnap/load_path_cache/loaded_features_index.rb:100:in `register'
# .../gems/bootsnap-1.9.3/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:22:in `require_with_bootsnap_lfi'
# .../gems/bootsnap-1.9.3/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:31:in `require'
# .../gems/zeitwerk-2.5.2/lib/zeitwerk/kernel.rb:36:in `require'
# .../bundler/gems/rails-6a0f6c4d70b1/actionmailbox/lib/action_mailbox/engine.rb:9:in `<main>'
# .../gems/bootsnap-1.9.3/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:23:in `require'
# .../gems/bootsnap-1.9.3/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:23:in `block in require_with_bootsnap_lfi'
# .../gems/bootsnap-1.9.3/lib/bootsnap/load_path_cache/loaded_features_index.rb:100:in `register'
# .../gems/bootsnap-1.9.3/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:22:in `require_with_bootsnap_lfi'
# .../gems/bootsnap-1.9.3/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:31:in `require'
# .../gems/zeitwerk-2.5.2/lib/zeitwerk/kernel.rb:36:in `require'
# ./config/application.rb:11:in `<top (required)>'
# ./config/environment.rb:2:in `require_relative'
# ./config/environment.rb:2:in `<top (required)>'
# ./spec/rails_helper.rb:4:in `require'
# ./spec/rails_helper.rb:4:in `<top (required)>'
No examples found.


Finished in 0.00005 seconds (files took 0.57758 seconds to load)
0 examples, 0 failures, 1 error occurred outside of examples

Answer 1

对于 Rails 6

将gem 'net-smtp', require: false添加到您的Gemfile并运行bundle 。

同样，我假设您可能对net-imap和net-pop有问题，因此必须添加它们，直到发布新的mail gem 版本。

gem 'net-smtp', require: false
gem 'net-imap', require: false
gem 'net-pop', require: false

对于 Rails 7

2022 年 1 月 6 日，Rails 7.0.1 发布：

此版本的重点是支持 Ruby 3.1

在其他与 Ruby 3.1 相关的问题中，它解决了这个问题。 所以升级到 Rails >= 7.0.1 。

---

相关的拉取请求和问题：

• mikel/mail：添加以前的默认 gem 作为 Ruby 3.1 兼容性的依赖项
• 为错误报告模板添加 net/smtp gem 以支持 Ruby 3.1

Answer 2

在生产模式下运行 Rails 时，我遇到了同样的问题。 （Ruby 3，导轨 6.1）

将这行代码复制并粘贴到Gemfile ：

gem 'net-smtp', require: false
gem 'net-imap', require: false
gem 'net-pop', require: false