I have email-ext sending an email to upstream committers, which seems to work in general, when there is 1 upstream job that kicked this downstream job.

But when there is a quiet period, and there are multiple upstream jobs that were responsible for kicking this single downstream job, only one of the upstream job committers is utilized.

For the job itself, the 'display upstream changes' shows the multiple jobs, each with different commits and users. But the email only grabs the upstream committer of one of those jobs.

My "display upstream changes" on the job's main page shows:

Started by upstream project xxx build number 4747
originally caused by:

• Started by upstream project yyy build number 425
  originally caused by:
• Started by upstream project zzz build number 725
  originally caused by:
• Started by Github push by user1

Started by upstream project xxx build number 4742
originally caused by:

• Started by upstream project qqq build number 60
  originally caused by:
• Started by upstream project rrr build number 111
  originally caused by:
• Started by Github push by user2

(this particular job had 5 upstream projects that were responsible for triggering this single job – all with 5 different commits/users. The "Github push" were html links that I've removed for this bug report, but all resolved with commit details, etc).

But even though this job's page showed the upstream project and commits and committers, only the first one in the list was chosen to add for the email.

In other cases where there was one 'started by upstream project' that had 2 committers, both committers were in the email. But it looks like the problem revolves around the scenario where there is more than 1 "started by upstream project" at the root level.