Patch-Magento_Base-setup-upgrade_2.2.6.patch

--- setup/src/Magento/Setup/Model/Installer.php
+++ setup/src/Magento/Setup/Model/Installer.php
@@ -1107,6 +1107,14 @@
      */
     private function cleanCaches()
     {
+        //PATCH
+        if (file_exists(\Magento\Framework\App\ObjectManager\ConfigLoader\Compiled::getFilePath(\Magento\Framework\App\Area::AREA_GLOBAL))) {
+            $this->objectManagerProvider->get()->get('Magento\Framework\App\Cache')->clean();
+            $this->log->log('Cache cleared successfully (compiled fix)');
+            return;
+        }
+        //PATCH END
+
         /** @var \Magento\Framework\App\Cache\Manager $cacheManager */
         $cacheManager = $this->objectManagerProvider->get()->get('Magento\Framework\App\Cache\Manager');
         $types = $cacheManager->getAvailableTypes();