Resolution: Not A Defect
CentOS 7 Server
Jenkins 2.2 from standard Docker image
latest versions of plugins:
- pipeline plugin 2.1
- pipeline multibranch plugin 2.3
- Mercurial plugin 1.54
I created multibranch pipeline with Mercurial SCM. But after the creation, configuration "Discard old builds" in the subtasks are not setted up. As a result, the discarding don't performed.