In Drupal 7 how do you output array objects to be view able in watchdog error reports? For some reason I couldn't use devel to debug output object arrays. Is there a way to output the array data to watchdog error reporting? This would also solve the issue of having to install or enable another module.
You can use watchdog but the message part should be translatable, so any variables should use placeholders defined in the variables array. Check out format_string to see how these should work. 

watchdog(
  'my_module_name',
  'Here is the printed variable: &lt;pre&gt;@placeholder_name&lt;/pre&gt;',
  array('@placeholder_name' =&gt; print_r( $my_variable, TRUE)),
  WATCHDOG_INFO
);


Also, convention dictates that the first parameter, $type, should be the module name calling watchdog.