By default, Pipeline builds can run concurrently.
The milestone step forces all builds to go through in order, so an older build will never be allowed pass
a milestone (it is aborted) if a newer build already passed it.
In general this step grants:
- Builds pass milestones in order (taking the build number as sorter field).
- Older builds will not proceed (they are aborted) if a newer one already passed the milestone.
- When a build passes a milestone, any older build that passed the previous milestone but not this one is aborted.
- Once a build passes the milestone, it will be never aborted by a newer build that didn't pass the milestone yet.