When using a Pathname instead of a String for the file argument, I get an error.
See the following code:
require 'exiftool'
require 'pathname'
path=Pathname.new('p./public/images/test.jpg')
Exiftool.new(path)
will result in
NoMethodError: undefined method empty?' for #<Pathname:p./public/images/test.jpg>
the workaround is to convert the Pathname to a String:
Exiftool.new(path.to_s)
Ruby version 2.3.1