This idea has been merged into another idea. To comment or vote on this idea, please visit CCI-I-316 Trigger new build when a Pull Request is opened.
New Workflow Filter: Branches>Pull_Request Merged
Currently a push to a branch may be ran before a pull request is created and a new job will not be triggered when a pull request is opened. This can cause issues for developers who are relying on the `CIRCLE_PULL_REQUEST` env var for certain scripts.
Currently the only solution is to enable "Build Pull Requests Only" in the advanced settings for the project as a whole.
pull_request: true can be used as a boolean to filter non-pull_request jobs.