How to fully reproduce dev environment with ddev?

I'm git cloneing a project that is run with ddev. After doing

• git clone
• ddev config
• ddev start

and opening the hosted site, I get various errors, for instance:

    Warning: include_once(/var/www/html/includes/file.phar.inc): failed to open stream: No such file or directory in include_once() (line 716 of /var/www/html/includes/bootstrap.inc).
    Warning: include_once(): Failed opening '/var/www/html/includes/file.phar.inc' for inclusion (include_path='.:/usr/share/php') in include_once() (line 716 of /var/www/html/includes/bootstrap.inc).
    Error: Call to undefined function file_register_phar_wrapper() in drupal_environment_initialize() (line 717 of /var/www/html/includes/bootstrap.inc).
    Notice: Undefined index: base_url in file_create_url() (line 395 of /var/www/html/includes/file.inc).
    Notice: Undefined index: base_url in file_create_url() (line 395 of /var/www/html/includes/file.inc).
    Notice: Undefined index: base_path in base_path() (line 2930 of /var/www/html/includes/common.inc).
    Notice: Undefined index: base_path in base_path() (line 2930 of /var/www/html/includes/common.inc).

My colleagues don't get this of course. And the file file.phar.inc is indeed not present in the entire repo. This shows that this isn't a small bug in the Drupal code but rather something is different about our environments. How can I get a reproducible build running on my machine? Should I copy the entire .ddev folder from a working installation to my machine and rerun ddev?

ps. I did try copying down file.phar.inc file from the Drupal source and this got rid of the include error, but generated many more other ones. I could go down the rabbit hole of fixing all of them but it works on other devs' machines, so I think it's an environment issue.

Did you run ddev composer install from the project root?

Newer versions of Drupal use composer to manage dependencies. Generally, composer projects don't commit these files so you need to "install" them after cloning: composer install

Because your project is using ddev, you need to run ddev composer install (which runs the command inside the web container) to make sure composer uses your site's PHP version.