TYPO3 Core

On step 4 (when the actual installation happens):

Even if there has been an error, the progress bar conveys that it is still doing something.

In the case I have at hand here, the AJAX request returned with 500 and this HTML response:

Symfony\Component\DependencyInjection\Exception\RuntimeException

Cannot autowire service "TYPO3\CMS\Core\DataHandling\SoftReference\SoftReferenceParserFactory": 
argument "$runtimeCache" of method "__construct()" references interface "TYPO3\CMS\Core\Cache\Frontend\FrontendInterface" 
but no such service exists. You should maybe alias this interface to one of these existing services: 
...

Whatever the error is, we should make the user aware of that occurrence and where to find the log.

In my opinion it would help the user to directly show him/her the returned error message but I am not sure how others think about it.