mktemp: handle dirs with restricted permissions

Library/Homebrew/mktemp.rb

@@ -62,9 +62,23 @@ class Mktemp
     begin
       Dir.chdir(tmpdir) { yield self }
     ensure
-      ignore_interrupts { rm_rf(tmpdir) } unless retain?
+      ignore_interrupts { chmod_rm_rf(tmpdir) } unless retain?
     end
   ensure
     ohai "Temporary files retained at:", @tmpdir.to_s if retain? && !@tmpdir.nil? && !@quiet
   end
+
+  private
+
+  def chmod_rm_rf(path)
+    if path.directory? && !path.symlink?
+      chmod("u+rw", path) if path.owned? # Need permissions in order to see the contents
+      path.children.each { |child| chmod_rm_rf(child) }
+      rmdir(path)
+    else
+      rm_f(path)
+    end
+  rescue
+    nil # Just skip this directory.
+  end
 end