当我试图运行 耙子 (也有 轨 commands）命令，我得到这个错误。
Rake aborted! cannot load such file -- arel/visitor/mysql
/config/application.rb:7:in <top (required)>
/Rakefile:4:in 'require_relative'
MySql数据库工作得很好，我在Gemfile中添加了gem'mysql2'。
使用 --追踪 参数：Ruby--版本：2.6.6Rails--版本：6.0.3.1Rake--版本：13.0.1
rake aborted!
LoadError: cannot load such file -- arel/visitors/mysql
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activesupport-6.0.3.1/lib/active_support/dependencies.rb:324:in `require'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activesupport-6.0.3.1/lib/active_support/dependencies.rb:324:in `block in require'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activesupport-6.0.3.1/lib/active_support/dependencies.rb:291:in `load_dependency'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activesupport-6.0.3.1/lib/active_support/dependencies.rb:324:in `require'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activerecord-6.0.3.1/lib/arel/visitors.rb:8:in `<top (required)>'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activesupport-6.0.3.1/lib/active_support/dependencies.rb:324:in `require'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activesupport-6.0.3.1/lib/active_support/dependencies.rb:324:in `block in require'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activesupport-6.0.3.1/lib/active_support/dependencies.rb:291:in `load_dependency'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activesupport-6.0.3.1/lib/active_support/dependencies.rb:324:in `require'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activerecord-6.0.3.1/lib/arel.rb:17:in `<top (required)>'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activesupport-6.0.3.1/lib/active_support/dependencies.rb:324:in `require'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activesupport-6.0.3.1/lib/active_support/dependencies.rb:324:in `block in require'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activesupport-6.0.3.1/lib/active_support/dependencies.rb:291:in `load_dependency'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activesupport-6.0.3.1/lib/active_support/dependencies.rb:324:in `require'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activerecord-6.0.3.1/lib/active_record.rb:29:in `<top (required)>'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activesupport-6.0.3.1/lib/active_support/dependencies.rb:324:in `require'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activesupport-6.0.3.1/lib/active_support/dependencies.rb:324:in `block in require'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activesupport-6.0.3.1/lib/active_support/dependencies.rb:291:in `load_dependency'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activesupport-6.0.3.1/lib/active_support/dependencies.rb:324:in `require'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activerecord-6.0.3.1/lib/active_record/railtie.rb:3:in `<top (required)>'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activesupport-6.0.3.1/lib/active_support/dependencies.rb:324:in `require'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activesupport-6.0.3.1/lib/active_support/dependencies.rb:324:in `block in require'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activesupport-6.0.3.1/lib/active_support/dependencies.rb:291:in `load_dependency'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activesupport-6.0.3.1/lib/active_support/dependencies.rb:324:in `require'
/home/sneffar/working-dir/permission/config/application.rb:7:in `<top (required)>'
/home/sneffar/working-dir/permission/Rakefile:4:in `require_relative'
/home/sneffar/working-dir/permission/Rakefile:4:in `<top (required)>'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/rake-13.0.1/lib/rake/rake_module.rb:29:in `load'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/rake-13.0.1/lib/rake/rake_module.rb:29:in `load_rakefile'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/rake-13.0.1/lib/rake/application.rb:703:in `raw_load_rakefile'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/rake-13.0.1/lib/rake/application.rb:104:in `block in load_rakefile'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/rake-13.0.1/lib/rake/application.rb:186:in `standard_exception_handling'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/rake-13.0.1/lib/rake/application.rb:103:in `load_rakefile'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/rake-13.0.1/lib/rake/application.rb:82:in `block in run'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/rake-13.0.1/lib/rake/application.rb:186:in `standard_exception_handling'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/rake-13.0.1/lib/rake/application.rb:80:in `run'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/rake-13.0.1/exe/rake:27:in `<top (required)>'
/home/sneffar/.rbenv/versions/2.6.6/bin/rake:23:in `load'
/home/sneffar/.rbenv/versions/2.6.6/bin/rake:23:in `<main>'
Ruby --version : 2.6.6Rails --version : 6.0.3.1Rake --version: 13.0.1。
我认为你应该删除arel。
gem uninstall arel
之后运行。
bundle install
这应该可以解决这个问题。
我也面临着这一点，并同意Nezir.I相信，在我的情况下，发生这种情况是因为这样的行动：MySQL 5.7.30 -> MySQL 8.0.20 -> MySQL 5.7.30第一次我有MySQL 5.7.30它是罚款与bundle exec rake db:create db:structure:load。