Constant META_ENVIRONMENT_URL 

pub const META_ENVIRONMENT_URL: &str = "environment_url";

Records a Step’s environment:url: value verbatim. Stamped by the GitLab parser when the job declares an environment: mapping with a url: field. Consumed by untrusted_ci_var_in_shell_interpolation because environment:url: is rendered by the GitLab UI and any predefined-CI-var interpolated into it is a stored-XSS / open-redirect sink.