Both the master and develop branch are supposed to be working for people at all times. For experiments in the context of issues and generally features not yet ready for prime time, there is factory.
You have probably come here, because you were asked to checkout a change made for you on factory.
How to get
Word of Warning
The factory may include all kinds of stupid mistakes, e.g. not being executable with all versions, crashing, not working at all. So please use it only for the issue at hand or even more than usually on your own risk. Once confirmed, fixes will normally appear in either hotfixes or pre-releases shortly.