Some CI systems do this automatically for PR builds, e.g. TravisCI: > Rather than build the commits that have been pushed to the branch the pull request is fro

Some CI systems do this automatically for PR builds, e.g. TravisCI: > Rather than build the commits that have been pushed to the branch the pull request is from, we build the merge between the source branch and the upstream branch. https://docs.travis-ci.com/user/pull-requests/#how-pull-requests-are-built https://docs.travis-ci.com/user/pull-requests/#how-pull-requ...