<!--IssueSummary start--> <details> <summary> Everyone can contribute. [Help move this issue forward](https://handbook.gitlab.com/handbook/marketing/developer-relations/contributor-success/community-contributors-workflows/#contributor-links) while earning points, leveling up and collecting rewards. </summary> - [Close this issue](https://contributors.gitlab.com/manage-issue?action=close&projectId=278964&issueIid=19597) </details> <!--IssueSummary end--> ### Description When a merge request fails for reasons other than merge conflicts, there is no notification to the user. As such errors are not spotted immediately for rectification. Reasons include: - commit hook - commit squash failure - Any error which results in 'An error occurred while merging. Try again.' (for example: #384017) ### Proposal Send a notification in the same way notifications are sent for a pipeline failure or a merge request merge success. ### Links / references https://gitlab.zendesk.com/agent/tickets/82782 Make sure these are completed before closing the issue, with a link to the relevant commit. - [ ] [Feature assurance](https://about.gitlab.com/handbook/product/#feature-assurance) - [ ] Documentation - [ ] Added to [features.yml](https://gitlab.com/gitlab-com/www-gitlab-com/blob/master/data/features.yml)