Returns TRUE if a Drupal installation is currently being attempted.
function drupal_installation_attempted() {
// This cannot rely on the MAINTENANCE_MODE constant, since that would prevent
// tests from using the non-interactive installer, in which case Drupal
// only happens to be installed within the same request, but subsequently
// executed code does not involve the installer at all.
// @see install_drupal()
return isset($GLOBALS['install_state']) && empty($GLOBALS['install_state']['installation_finished']);
}