Pipeline intermittent lint failures

Summary

Intermittent pipeline lint failures. Many times, the next commit will cause the pipeline to run. Testing the yaml with the lint tool does now show any issues.

What is the current bug behavior?

Pipeline will fail lint with only config contains unknown keys: variables.

What is the expected correct behavior?

Pipeline should run.

Running Gitlab 11.0.2 with runner 0.11.0.

Customer ticket -> https://gitlab.zendesk.com/agent/tickets/100695 (internal only)

(If you can, link to the line of code that might be responsible for the problem)

Can we get some guidance on the best way to troubleshoot?

/cc @jlenny