The Jenkins local documentation for Pipelines declares that the following global variables will be populated:

CHANGE_ID
CHANGE_URL
CHANGE_TITLE
CHANGE_AUTHOR
CHANGE_AUTHOR_DISPLAY_NAME
CHANGE_AUTHOR_EMAIL
CHANGE_TARGET

The lack of data in these variables results in the following severely reduced functionality.

• Unable to effectively notify users of pull request related build status via StashNotifier, HipChatNotifier, email and other notification plugins
• Unable to effectively notify committers of build failures
• Unable to detect pull requests without string parsing (which is hacky imo)