is there a way to make (some) tests run serially? we have some tests that run against a live system and can't be run in parallel. At the moment we're doing two calls to

./pants test

with the non-parallel ones being called with

--test-debug

or whatever the flag is. But we're adding more live-systems that can be run in parallel with each other, and as things grow everything's getting slower by multiples. e.g. tests

a_1, a_2, a_3

must be run serially. and

b_1, b_2, b_3

must be run serially. But

a_1

and

b_1

could be run in parallel. If not supported OOTB, is there a path to implementing this with a plugin?