Call original backtick using super

Library/Homebrew/cmd/update.rb

@@ -196,7 +196,7 @@ class Updater
   end
 
   def `(cmd)
-    out = Kernel.`(cmd) #`
+    out = super
     if $? && !$?.success?
       $stderr.puts out
       raise ErrorDuringExecution, "Failure while executing: #{cmd}"

Library/Homebrew/test/test_updater.rb

@@ -16,8 +16,8 @@ class UpdaterTests < Homebrew::TestCase
       @outputs[cmd] << output
     end
 
-    def `(cmd, *args)
-      cmd = "#{cmd} #{args*' '}".strip
+    def `(*args)
+      cmd = args.join(" ")
       if @expected.include?(cmd) and !@outputs[cmd].empty?
         @called << cmd
         @outputs[cmd].shift
@@ -25,8 +25,7 @@ class UpdaterTests < Homebrew::TestCase
         raise "#{inspect} unexpectedly called backticks: `#{cmd}`"
       end
     end
-
-    alias safe_system ` #`
+    alias_method :safe_system, :`
 
     def expectations_met?
       @expected == @called