[UI] Robustness for ::path

lib/cocoapods/user_interface.rb

@@ -145,7 +145,9 @@ module Pod
       #
       def path(pathname)
         if pathname
-          path = pathname.relative_path_from((config.podfile_path.dirname if config.podfile_path) || Pathname.pwd)
+          from_path = config.podfile_path.dirname if config.podfile_path
+          from_path ||= Pathname.pwd
+          path = Pathname(pathname).relative_path_from(from_path)
           "`#{path}`"
         else
           ''