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

【问题标题】：Rails 7 Ruby 3.1 LoadError: cannot load such file -- net/smtpRails 7 Ruby 3.1 LoadError：无法加载此类文件--net/smtp
【发布时间】：2021-12-27 20:40:48
【问题描述】：

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

【问题讨论】：

标签： ruby-on-rails ruby ruby-on-rails-7 ruby-3.1

【解决方案1】：

UPD：在 2022 年 1 月 6 日 Rails 7.0.1 是released：

此版本的重点是为 Ruby 3.1 带来支持

在其他与 Ruby 3.1 相关的问题中，它为这个问题带来了a fix。所以升级到 Rails >= 7.0.1。

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until 一个新的mail gem 版本已发布。