Fix bug.

lib/tasks/exec_command.rake

@@ -169,10 +169,11 @@ namespace :exec_commands do
               data_str = data.to_s
               if data.include?("\n") || outputs.empty?
                 output_lines = data_str.split("\n")
-                first_output = nil
+                first_output = output_lines[0]
                 if outputs.count != 0
-                  first_output = output_lines[0]
                   outputs[-1] += first_output
+                else
+                  outputs << first_output
                 end
                 new_arr = output_lines[1..-1]
                 if data_str[-1] == "\n"