TYPO3 Core

Using a middleware like this:

# Add custom middleware to default Guzzle handler stack
$GLOBALS['TYPO3_CONF_VARS']['HTTP']['handler'][] =
   (\TYPO3\CMS\Core\Utility\GeneralUtility::makeInstance(\ACME\Middleware\Guzzle\CustomMiddleware::class))->handler();

it's not possible to use xml2array, instead an error-message is thrown:

[CRITICAL] request="c379d512eb551" component="TYPO3.CMS.Core.Error.ProductionExceptionHandler": Core: Exception handler (WEB): Uncaught TYPO3 Exception: #1549446998: TYPO3\CMS\Core\Cache\CacheManager can not be injected/instantiated during ext_localconf.php loading. Use lazy loading instead. | LogicException thrown in file typo3/sysext/core/Classes/ServiceProvider.php in line 97.