"Block build if parent plans have unbuilt changes" still allows the triggering of child builds while parent is running

Duplication Steps

1. Create the following build plans with the Repository Polling trigger type (60 second intervals):
   • Plan A
   • Plan B
   • Plan C
   • Plan D
   • Plan E
2. Configure parent/child relationship as follows:

   Parent	Child
   Plan A	Plan B
   Plan B	Plan C
   Plan C	Plan D
   Plan D	Plan E

3. Select the following options under Advanced options:
   • Trigger dependencies only when all stages have been run successfully
   • Enable dependencies for all branches of this plan
   • Block build if parent plans have unbuilt changes
4. Commit changes to Plan A, Plan D, and Plan E at once

You will notice Plan E does adhere to the blocking strategy but also triggers Plan D to build while Plan A is running and was triggered by Plan D to build initially.

Workaround

Remove triggers from child plan and create separate build plans for the repositories that need to be committed to individually.