Clarify dependency between project builds feature and "pipelines must suceed"
We received a bug report from a customer https://gitlab.com/gitlab-org/gitlab-ce/issues/57291 who thought that by disabling the builds from the project features, while leaving "Pipelines must succeed" checkbox enabled, it would ignore existing failing pipelines. It turned out that if "Pipelines must succeed" is enabled and there are existing failing pipelines, the Merge Request cannot be merged even if project builds are disabled. This is an expected behavior.
There seems to be some confusion around the implications of these 2 features, perhaps we can clarify that:
Disabling project builds does not mean that no pipelines will be created, because the user can still make use of external pipelines (e.g. TravisCI) while benefiting of the integrations with the Merge Request. The feature "Pipelines must succeed" will still take in consideration the status of the pipelines (whether they are displayed or not depending on the builds enabled/disabled).
Existing docs around these topics: