class Sprockets::AssetAttributes

def logical_path

path will be incorrect.
shaddowed in the path, but is required relatively, its logical
This has some known issues. For an example if a file is

Reverse guess logical path for fully expanded path. 
def logical_path
  raise ArgumentError unless pathname.absolute?
  if root_path = environment.paths.detect { |path| pathname.to_s[path] }
    path = pathname.relative_path_from(Pathname.new(root_path)).to_s
    path = engine_extensions.inject(path) { |p, ext| p.sub(ext, '') }
    path = "#{path}#{engine_format_extension}" unless format_extension
    path
  else
    raise FileOutsidePaths, "#{pathname} isn't in paths: #{environment.paths.join(', ')}"
  end
end