Problem:

If the Prevent unregistered user spend feature is enabled for your Gitlab project, you might see that your builds fail with the following error message: block-unregistered-user.

When you sign up to CircleCI with your email address, you can accept an invite to a Gitlab project, you will be able to view and follow the project and trigger builds as long as builds are not restricted to registered users. However, if you have not connected your Gitlab user to your CircleCI account upon sign-up, you will not be considered a registered user of the organization and our system will prevent you from triggering a build if the Prevent unregistered user spend feature is enabled for the organization.

Solution:

You can follow the below steps to connect your Gitlab user to your CircleCI account:

1. Log in with your email address and password on CircleCI
2. Navigate to your project settings page > Pipelines > Add Pipeline >  GitLab >  and click "Authorize". 
3. You can then confirm that CircleCI has the correct permissions by triggering a new build. 

Additional Resources:

• How to set up the Prevent unregistered user spend feature
• Steps to integrate GitLab projects with CircleCI