## Description Variables defined in `.gitlab-ci.yml` have lower precedence than their counterparts configured for the instance/group/project. Although this behavior seems unintuitive, I can see why this is the case. However, it can be very confusing to debug a pipeline with variables defined in `.gitlab-ci.yml` that get overwritten by instance/group/project-level variables. ## Proposal It's erroneous to define variables in `.gitlab-ci.yml` that are also defined at the instance/group/project-level as they will always be overruled by design. I therefore propose that defining such variables will result in a pipeline error in order to clearly communicate to the developer what's happening.