What I'm trying to achieve is share the failed tests to the next stage so that I can run a 'git bisect run' on each test class to find which commit exactly caused each failure.
So I have a Plan A, Test Stage containing 10jobs each of which run various tests. I then want to have a Bisect Stage that takes the failed tests from Test Stage and runs git bisect on each of them, that will then result in a series of SHAs that list Failed.TestA=SHA1, Failed.TestD=SHA2.