<!-- * Use this issue template for suggesting new docs or updates to existing docs. Note: Doc work as part of feature development is covered in the Feature Request template. * For issues related to features of the docs.gitlab.com site, see https://gitlab.com/gitlab-org/gitlab-docs/issues/ * For information about documentation content and process, see https://docs.gitlab.com/ee/development/documentation/ --> <!-- Type of issue --> <!-- Un-comment the line for the applicable doc issue type to add its label. Note that all text on that line is deleted upon issue creation. --> <!-- /label gitlab-ce~9444929 - New doc needed to cover a new topic or use case. --> <!-- /label gitlab-ce~9444930 - Improving an existing doc; e.g. adding a diagram, adding or rewording text, resolving redundancies, cross-linking, etc. --> <!-- /label gitlab-ce~9444931 - Review a page or group of pages in order to plan and implement major improvements/rewrites. --> <!-- /label gitlab-ce~9444932 - Anything else. --> ### Problem to solve <!-- Include the following detail as necessary: * What product or feature(s) affected? * What docs or doc section affected? Include links or paths. * Is there a problem with a specific document, or a feature/process that's not addressed sufficiently in docs? * Any other ideas or requests? --> The [documentation](https://docs.gitlab.com/ee/update/upgrading_from_source.html) concerning Gitlab update miss important information about changes brought by a new version. ### Further details <!-- * Any concepts, procedures, reference info we could add to make it easier to successfully use GitLab? * Include use cases, benefits, and/or goals for this work. * If adding content: What audience is it intended for? (What roles and scenarios?) For ideas, see personas at https://design.gitlab.com/research/personas or the persona labels at https://gitlab.com/groups/gitlab-org/-/labels?utf8=%E2%9C%93&subscribed=&search=persona%3A --> I recently updated my self-hosted instance to v12.1 and I was surprised my Merge Request pipelines failed. I had to dig into the documentation to finally find [this page](https://docs.gitlab.com/ee/ci/merge_request_pipelines/index.html) stating that > Pipelines for merge requests are incompatible with CI/CD for external repositories. I use CI/CD for external repositories. If I had been informed that updating would break my CI, maybe I would have taken my time to think about it. It is very unpleasant to discover this afterwards. ### Proposal <!-- Further specifics for how can we solve the problem. --> Please document this kind of breaking changes in the future. ### Who can address the issue <!-- What if any special expertise is required to resolve this issue? --> ### Other links/references <!-- E.g. related GitLab issues/MRs -->