Last updated August 26, 2013.
As stated in the release cycle policy, backwards compatibility-breaking API changes are only allowed during the API completion phase when they are needed to fix major and critical bugs and tasks. The flowchart below describes the process for resolving these issues:
Updating the issue summary
* Before you reach out to a core maintainer about a particular issue, ensure that the issue summary is up to date. It should contain the following information:
- The goal of the issue. (Why is it needed?)
- Why the issue is major or critical.
- A summary of the API changes introduced by the patch.
See the issue summary instructions for more information.
Asking a maintainer
** When possible, work with a component maintainer for the component to escalate the issue to a core maintainer. The core maintainers for Drupal 8 are Dries, catch, webchick, and alexpott. Ping them in IRC (or ask effulgentsia or xjm to forward on a question about a specific issue).