We are trying to determine if individual builds are started based on a PR. In the CircleCI UI, we can see that the build is associated with a PR, but none of the PR environment variables are present (e.g. CIRCLE_PULL_REQUEST, CIRCLE_PR_NUMBER, etc…). We have setup a workflow with multiple stages and would like to filter some jobs/stages base on if it is a PR build.
Is there some setting in CircleCI or GitHub that I need to set in order for these values to be included in the CircleCI environment variables?
In the example above, it should have a CIRCLE_PR_NUMBER=4
and a valid PR URL in CIRCLE_PULL_REQUEST
.