It is not possible to use reference/anchors/extend in **stages**. Following is the validation error: `This GitLab CI configuration is invalid: stages config should be an array of strings.` ``` yaml .build-stages: stages: - build-binary - build-deb - build-ova stages: - prebuild - !reference [.build-stages, stages] - postbuild dependency-scan: stage: prebuild script: - echo "dependency-scan" ova-scan: stage: postbuild script: - echo "ova-scan" ``` Follow is the full configuration of above .gitlab-ci.yaml: ``` yaml --- ".build-stages": stages: - build-binary - build-deb - build-ova stages: - ".pre" - prebuild - - build-binary - build-deb - build-ova - postbuild - ".post" dependency-scan: stage: prebuild script: - echo "dependency-scan" ova-scan: stage: postbuild script: - echo "ova-scan" ```