Troubleshooting

Problem

undefined method `width' for #<#<Class:0x8af4788>:0x8af5b38>

Dragonfly.app.configure do
  plugin :imagemagick
end

Problem

Command failed ('identify' '-ping' '-format' '%m %w %h' '/tmp/RackMultipart20140816-22639-7n8mxh') with exit status 127 and stderr sh: 1: identify: not found 

Install imagemagick