Additional uncaught exception thrown while handling exception.

Original

Error: Undefined constant "Drupal\error_page\DRUPAL_TEST_IN_CHILD_SITE" in Drupal\error_page\ErrorPageErrorHandler::handleError() (line 68 of /var/www/html/docroot/modules/contrib/error_page/src/ErrorPageErrorHandler.php).

Drupal\error_page\ErrorPageErrorHandler::handleError()
trigger_error() (Line: 113)
Drupal\Core\Site\Settings::get() (Line: 16)
Drupal\Core\Serialization\Yaml::decode() (Line: 44)
Drupal\Core\Extension\InfoParserDynamic->parse() (Line: 47)
Drupal\Core\Extension\InfoParser->parse() (Line: 216)
Drupal\Core\Extension\DatabaseDriver->getModuleInfo() (Line: 166)
Drupal\Core\Extension\DatabaseDriver->getAutoloadInfo() (Line: 101)
Drupal\Core\Extension\DatabaseDriver->load() (Line: 116)
Drupal\Core\Extension\DatabaseDriver->getInstallTasks() (Line: 1233)
install_database_errors() (Line: 1190)
install_verify_database_settings() (Line: 389)
install_begin_request() (Line: 118)
install_drupal() (Line: 53)

Additional

Error: Undefined constant "Drupal\error_page\DRUPAL_TEST_IN_CHILD_SITE" in Drupal\error_page\ErrorPageErrorHandler::logError() (line 149 of /var/www/html/docroot/modules/contrib/error_page/src/ErrorPageErrorHandler.php).

Drupal\error_page\ErrorPageErrorHandler::logError() (Line: 102)
Drupal\error_page\ErrorPageErrorHandler::handleException()