testing: parallel test output reported in non-deterministic order #26440
Description
I have a test with parallel subtests. A few are failing. Every time I run the test, the failures come out in a different order, presumably depending on which ones finish first. This makes it hard to see at a glance what is different each time I make a tweak and re-run the tests.
Given that we're saving up the output to print at the end of the test anyway, we should also arrange to order the test results - at least all the parallel ones - in the order they started, not the order they finished.
/cc @mpvl