【问题标题】：`@@{' is not allowed as a class variable name (SyntaxError) while using s3 gem + rails 4.1.5使用 s3 gem + rails 4.1.5 时，`@@{' 不允许作为类变量名 (SyntaxError)
【发布时间】：2015-01-27 01:55:13
【问题描述】：

我知道已经有人问过这类问题。

我使用s3 gem 将我的文件上传到s3 存储桶中。但是在s3 gem 安装之后，当我启动 rails server 时，它会显示这个错误：

    /var/lib/gems/1.9.1/gems/aws-s3-0.6.3/lib/aws/s3/extensions.rb:223:in `class_eval': /var/lib/gems/1.9.1/gems/aws-s3-0.6.3/lib/aws/s3/extensions.rb:223: `@@{' is not allowed as a class variable name (SyntaxError)
/var/lib/gems/1.9.1/gems/aws-s3-0.6.3/lib/aws/s3/extensions.rb:223: syntax error, unexpected $end
        unless defined? @@{:instance_writer=>true}
                          ^
    from /var/lib/gems/1.9.1/gems/aws-s3-0.6.3/lib/aws/s3/extensions.rb:223:in `block in cattr_reader'
    from /var/lib/gems/1.9.1/gems/aws-s3-0.6.3/lib/aws/s3/extensions.rb:222:in `each'
    from /var/lib/gems/1.9.1/gems/aws-s3-0.6.3/lib/aws/s3/extensions.rb:222:in `cattr_reader'
    from /var/lib/gems/1.9.1/gems/aws-s3-0.6.3/lib/aws/s3/extensions.rb:258:in `cattr_accessor'
    from /var/lib/gems/1.9.1/gems/activesupport-4.1.5/lib/active_support/cache.rb:155:in `<class:Store>'
    from /var/lib/gems/1.9.1/gems/activesupport-4.1.5/lib/active_support/cache.rb:154:in `<module:Cache>'
    from /var/lib/gems/1.9.1/gems/activesupport-4.1.5/lib/active_support/cache.rb:14:in `<module:ActiveSupport>'
    from /var/lib/gems/1.9.1/gems/activesupport-4.1.5/lib/active_support/cache.rb:12:in `<top (required)>'
    from /var/lib/gems/1.9.1/gems/activesupport-4.1.5/lib/active_support/dependencies.rb:247:in `require'
    from /var/lib/gems/1.9.1/gems/activesupport-4.1.5/lib/active_support/dependencies.rb:247:in `block in require'
    from /var/lib/gems/1.9.1/gems/activesupport-4.1.5/lib/active_support/dependencies.rb:232:in `load_dependency'
    from /var/lib/gems/1.9.1/gems/activesupport-4.1.5/lib/active_support/dependencies.rb:247:in `require'
    from /var/lib/gems/1.9.1/gems/jbuilder-2.2.5/lib/jbuilder/jbuilder_template.rb:3:in `<top (required)>'
    from /var/lib/gems/1.9.1/gems/activesupport-4.1.5/lib/active_support/dependencies.rb:247:in `require'
    from /var/lib/gems/1.9.1/gems/activesupport-4.1.5/lib/active_support/dependencies.rb:247:in `block in require'
    from /var/lib/gems/1.9.1/gems/activesupport-4.1.5/lib/active_support/dependencies.rb:232:in `load_dependency'
    from /var/lib/gems/1.9.1/gems/activesupport-4.1.5/lib/active_support/dependencies.rb:247:in `require'
    from /var/lib/gems/1.9.1/gems/jbuilder-2.2.5/lib/jbuilder/railtie.rb:2:in `<top (required)>'
    from /var/lib/gems/1.9.1/gems/activesupport-4.1.5/lib/active_support/dependencies.rb:247:in `require'
    from /var/lib/gems/1.9.1/gems/activesupport-4.1.5/lib/active_support/dependencies.rb:247:in `block in require'
    from /var/lib/gems/1.9.1/gems/activesupport-4.1.5/lib/active_support/dependencies.rb:232:in `load_dependency'
    from /var/lib/gems/1.9.1/gems/activesupport-4.1.5/lib/active_support/dependencies.rb:247:in `require'
    from /var/lib/gems/1.9.1/gems/jbuilder-2.2.5/lib/jbuilder.rb:317:in `<top (required)>'
    from /var/lib/gems/1.9.1/gems/bundler-1.6.2/lib/bundler/runtime.rb:76:in `require'
    from /var/lib/gems/1.9.1/gems/bundler-1.6.2/lib/bundler/runtime.rb:76:in `block (2 levels) in require'
    from /var/lib/gems/1.9.1/gems/bundler-1.6.2/lib/bundler/runtime.rb:72:in `each'
    from /var/lib/gems/1.9.1/gems/bundler-1.6.2/lib/bundler/runtime.rb:72:in `block in require'
    from /var/lib/gems/1.9.1/gems/bundler-1.6.2/lib/bundler/runtime.rb:61:in `each'
    from /var/lib/gems/1.9.1/gems/bundler-1.6.2/lib/bundler/runtime.rb:61:in `require'
    from /var/lib/gems/1.9.1/gems/bundler-1.6.2/lib/bundler.rb:132:in `require'
    from /home/rick/rick/Projects/practice/sharebox/config/application.rb:7:in `<top (required)>'
    from /var/lib/gems/1.9.1/gems/railties-4.1.5/lib/rails/commands/commands_tasks.rb:79:in `require'
    from /var/lib/gems/1.9.1/gems/railties-4.1.5/lib/rails/commands/commands_tasks.rb:79:in `block in server'
    from /var/lib/gems/1.9.1/gems/railties-4.1.5/lib/rails/commands/commands_tasks.rb:76:in `tap'
    from /var/lib/gems/1.9.1/gems/railties-4.1.5/lib/rails/commands/commands_tasks.rb:76:in `server'
    from /var/lib/gems/1.9.1/gems/railties-4.1.5/lib/rails/commands/commands_tasks.rb:40:in `run_command!'
    from /var/lib/gems/1.9.1/gems/railties-4.1.5/lib/rails/commands.rb:17:in `<top (required)>'
    from bin/rails:4:in `require'
    from bin/rails:4:in `<main>'

有谁知道，如何解决这个错误？我应该尝试其他宝石吗？

【问题讨论】：

能否提供完整的跟踪错误？
我用完整的错误@rockskull 更新了我的问题
你看过这个答案吗：stackoverflow.com/a/25878748/906511 ?
@rockskull 我找到了解决方案。我做了什么，我安装了 aws-sdk gem。
很高兴听到这个消息。因此，请更新您的问题或发布答案，以便有相同问题的人可以看到解决方案。 ;)

标签： ruby amazon-s3 ruby-on-rails-4.2

【解决方案1】：

我们今天早上遇到了同样的问题。我们已经安装了这个 aws-sdk gem，但是昨天它更新到了第 2 版。似乎版本 2 不再解决此问题，所以我建议使用最新版本 1：1.61.0

【讨论】：

【解决方案2】：

是的，我刚刚遇到了这个问题并解决了。这是因为 AWS 将他们的 gem 更新到了 2.0。如果您根据他们发布的article 将 gem 更新到 2.0，则需要不同的配置。

如果您想使用之前的版本，只需更改 Gemfile 如下：

宝石文件

gem 'aws-sdk', '

【讨论】：