The installation was not successful, Composer returned the error code: 1

Hi,

I have tried to install Neos and creating my own empty, dummy site during the Setup wizard.
I have followed this doc page here using the Docker setup: https://docs.neos.io/cms/installation-development-setup/docker-and-docker-compose-setup

On step 4 “Create new Site” I have filled out the two textfields “Package Name (in form “Vendor.DomainCom”)” and “Site Name (e.g. “domain.com”)”.

After clicking Next I receive following error:

# The installation was not successful.

Composer returned the error code: 1

|Exception Code|1572187932|
| --- | --- |
|Exception Type|Neos\Flow\Package\Exception|
|Log Reference|20200801010804ea6a00|
|Thrown in File|Packages/Framework/Neos.Flow/Classes/Package/PackageManager.php|
|Line|408|

...

Neos\Flow\Package\PackageManager::createPackage("MyCompany.DemoSite", array|7|)

Data/Temporary/Development/SubContextDocker/Cache/Code/Flow_Object_Classes/Neos_SiteKickstarter_Service_GeneratorService.php
Original File: Packages/Application/Neos.SiteKickstarter/Classes/Service/GeneratorService.php

00045:     {
00046:         $this->packageManager->createPackage($packageKey, [
00047:             'type' => 'neos-site',
00048:             "require" => [
00049:                 "neos/neos" => "*",

Somehow the composer execution fails, but I don’t know why. Does anybody have an idea why this fails?

What would be the proper way to setup Neos with a blank, empty, dummy site?

Thanks for help!

Can you share the stack trace from your exception log (Log/Exceptions/20200801010804ea6a00.txt)?