Hi Daniel, Santiago, thx for the answer; I am not 100% satisfied, though ;).
For me, it actually boils down to what notion we have: (1) The builder hosts must provide reasonable entropy. (2) Software testsuites generally must work fine even with low entropy. In the past, I tended to go with (1) (which is one of the reasons mini- buildd recommends haveged). So I guess just going for both for now ;), so I will check how I can improve that specific doctest in mini-buildd. I am still sort of wondering how other testsuites behave in this respect (like gnupg, gcrypt)? Thx! S