Starting with stestr, could you explain why it was not good enough for your use case?
Stestr will not provide us with fixtures for django (for future use), also with the help of pytest, we probably would be able to unify html creation all across our projects. Also, xml exporting in different formats can help users with aggregating test statistics.
more of a general question if they are test only deps that wont be used at runtime which i think is the case in all of the above do they enven need to be in Global-requirements? ignoring the fact that devstack installes all test- requireemtes when it in stall packages which is a different topic if this is only used for generating html report for tests then it seams liek we would not need to corrdiate the software version. pytest is needed to generate coverage reports.