This really should be a check in TTM pipeline, but for now we just run it as we always did, but have it block staging projects
How to validate the yaml
For some reason, valid yaml is not supported - the indentation required is rather wild. But to check the syntax before commit, you can use the plugin locally:
wget https://github.com/tomzo/gocd-yaml-config-plugin/releases/download/0.9.0/yaml-config-plugin-0.9.0.jar
java -jar yaml-config-plugin-0.9.0.jar syntax sp1-stagings.gocd.yaml | grep -q '"valid":true'