I am evaluating Mautic for a personal project and installed a local development from a forked git repository. I installed DDEV on my system and then executed the .ddev/gitpod-setup-ddev.sh file which ran fine except for a port 80 issue. The PHPMyAdmin service is set up to use port 80 as well as the mautic-web service. I had to modify the config.yaml file to change the ports for mautic-web to use a different port. Once I had all of the services running I went to the web URL and was greeted with a missing Symfony/dotenv package. I then logged into the mautic-web service via the ddev ssh command and issued the compose install command to install Symfony/dotenv. After this I was greeted with a missing vendor/autoload.php file; I created the vendor folder and then created an empty autoload.php file.
After this I was able to see the install screen. The problem there is that I didn’t know the answers until I guessed it by looking at the MyPHPAdmin instance to see the db database created. I was wanting to enter mauticdb for the database name and mautic for the user name. I eventually guessed that the database name was db, the user name was db and the password was db.
Now I am able to give Mautic a try but it took me hours to bring up a development environment because of not understanding all of the setup needed for executing the install script. Not exactly your problem but hopefully this post will help others who are lost.