Try moving the 'variables' directive to the job template

.gitlab-ci.yml

@@ -14,10 +14,14 @@ workflow:
   stage: deploy
   tags:
     - docker
+  variables:
+    ROOT_RELATIVE_NAMESPACE: "${CI_PROJECT_NAMESPACE#$CI_PROJECT_ROOT_NAMESPACE}"
   script:
     - sed -i "s/%%BRANCH%%/$CI_COMMIT_BRANCH/g" src/index.html
     - mv src public
     - echo $SHELL
+    - echo $ROOT_RELATIVE_NAMESPACE
+    - echo $CI_ENVIRONMENT_URL
     - printenv
   artifacts:
     paths:
@@ -29,8 +33,6 @@ review:
   extends: .deploy
   rules:
     - if: $CI_COMMIT_BRANCH != $CI_DEFAULT_BRANCH
-  variables:
-    ROOT_RELATIVE_NAMESPACE: "${CI_PROJECT_NAMESPACE#$CI_PROJECT_ROOT_NAMESPACE}"
   environment:
     name: "review $CI_COMMIT_BRANCH"
     url: "https://${CI_PROJECT_ROOT_NAMESPACE}.${CI_PAGES_DOMAIN}/-${ROOT_RELATIVE_NAMESPACE}/${CI_PROJECT_NAME}/-/jobs/$CI_JOB_ID/artifacts/public/index.html"