Is there a means to pass some php.ini settings to the drush command? Running drush -d status results in this error: Drush command terminated abnormally due to an unrecoverable error. The full output is add below.


  Drush bootstrap phase : _drush_bootstrap_drupal_site() [0.12 sec, 7.41
  MB]
  [bootstrap] Initialized Drupal site default at sites/default [0.12
  sec, 7.41 MB]
  [notice] Cache HIT cid:
  5.7-commandfiles-2-c32acd775c18a90c5b41d0fc9accf5ab [0.13 sec, 7.41 MB]
  [debug] Drush bootstrap phase :
  _drush_bootstrap_drupal_configuration() [0.13 sec, 7.41 MB]                                                                       [bootstrap] Drush bootstrap phase : _drush_bootstrap_drupal_database()
  [0.16 sec, 9.16 MB]
  [bootstrap] Successfully connected to the Drupal database. [0.16 sec,
  9.16 MB]                                                                                        [bootstrap] Drush bootstrap phase : _drush_bootstrap_drupal_full()
  [0.17 sec, 9.16 MB]
  [bootstrap] Undefined index: sitename domain.module:2922 [1.24 sec,
  31.05 MB]                                                                                            [notice] Undefined index: path domain.module:2923 [1.24 sec, 31.05 MB]
  [notice] Drush command terminated abnormally due to an unrecoverable
  error. [1.24 sec, 31.06 MB]
  [error]


Is there a way to configure a separate php.ini for drush in the .drushrc file or in settings.php, or pass some settings on the drush invocation?
First, remember that php.ini for Command Line Interface is separate and has nothing to do with php.ini your webserver is using. To find where that file is, follow this question on SO as this is not really on-topic on Drupal Answers.

If you want to set some php.ini values in drushrc.php, you need to use ini_set() PHP function. Just remember that not all values are changeable like that, only the ones with PHP_INI_USER (or PHP_INI_ALL, of course) on this list.