求大神帮忙看看！这里是怎么了！我用 production 环境启动服务 报错！
网上查了很久，都没有类似的错误！
rake aborted!
Asset logical path has no extension: pa
/home/sc/.rvm/gems/ruby-2.0.0-p353/gems/sprockets-2.11.0/lib/sprockets/asset.rb:36:in initialize'
/home/sc/.rvm/gems/ruby-2.0.0-p353/gems/sprockets-2.11.0/lib/sprockets/base.rb:380:innew'
/home/sc/.rvm/gems/ruby-2.0.0-p353/gems/sprockets-2.11.0/lib/sprockets/base.rb:380:in build_asset'
/home/sc/.rvm/gems/ruby-2.0.0-p353/gems/sprockets-2.11.0/lib/sprockets/index.rb:94:inblock in build_asset'
/home/sc/.rvm/gems/ruby-2.0.0-p353/gems/sprockets-2.11.0/lib/sprockets/caching.rb:58:in cache_asset'
/home/sc/.rvm/gems/ruby-2.0.0-p353/gems/sprockets-2.11.0/lib/sprockets/index.rb:93:inbuild_asset'
/home/sc/.rvm/gems/ruby-2.0.0-p353/gems/sprockets-2.11.0/lib/sprockets/base.rb:287:in find_asset'
/home/sc/.rvm/gems/ruby-2.0.0-p353/gems/sprockets-2.11.0/lib/sprockets/index.rb:61:infind_asset'
/home/sc/.rvm/gems/ruby-2.0.0-p353/gems/sprockets-2.11.0/lib/sprockets/manifest.rb:211:in block in find_asset'
/home/sc/.rvm/gems/ruby-2.0.0-p353/gems/sprockets-2.11.0/lib/sprockets/manifest.rb:257:inbenchmark'
/home/sc/.rvm/gems/ruby-2.0.0-p353/gems/sprockets-2.11.0/lib/sprockets/manifest.rb:210:in find_asset'
/home/sc/.rvm/gems/ruby-2.0.0-p353/gems/sprockets-2.11.0/lib/sprockets/manifest.rb:119:inblock in compile'
/home/sc/.rvm/gems/ruby-2.0.0-p353/gems/sprockets-2.11.0/lib/sprockets/manifest.rb:118:in each'
/home/sc/.rvm/gems/ruby-2.0.0-p353/gems/sprockets-2.11.0/lib/sprockets/manifest.rb:118:incompile'
/home/sc/.rvm/gems/ruby-2.0.0-p353/gems/sprockets-rails-2.0.1/lib/sprockets/rails/task.rb:60:in block (3 levels) in define'
/home/sc/.rvm/gems/ruby-2.0.0-p353/gems/sprockets-2.11.0/lib/rake/sprocketstask.rb:146:inwith_logger'
/home/sc/.rvm/gems/ruby-2.0.0-p353/gems/sprockets-rails-2.0.1/lib/sprockets/rails/task.rb:59:in block (2 levels) in define'
/home/sc/.rvm/gems/ruby-2.0.0-p353/bin/ruby_executable_hooks:15:ineval'
/home/sc/.rvm/gems/ruby-2.0.0-p353/bin/ruby_executable_hooks:15:in `
Asset logical path has no extension: pa 这句话的意思是 pa 这个文件在资源的编译路径中，但是 pa 没有扩展名，所以产生了异常。 rails 里 sprockets 默认会把所有的包含在 Asset logical path 中的非 JS 或 CSS 文件编译，所以你到 app/assets/, lib/assets/, vendor/assets下找找看有没有pa这个文件，有的话给它加个扩展名，或者干脆把这个文件移除。