A new behavior after upgrading from 2.150.1 to 2.249.2, concurrently upgrading the Rebuilder plugin from 1.29 to 1.31:
A manual rebuild of a freestyle project now sets both BUILD_CAUSE_MANUALTRIGGER and BUILD_CAUSE_UPSTREAMTRIGGER to true.
A side effect of this change:
Suppose freestyle project_A triggers freestyle project_B. If project_A is manually rebuilt 10 times in a row, the console log of project_B's 10th run displays all 10 job numbers from project_A as a cascade of "originally caused by:"/"Started by upstream project ..." lines. The same cascade is displayed in the build summary page of project_B's 10th run.