From: Nikita Kniazev (nok.raven_at_[hidden])
Date: 2020-05-19 12:25:03
> I guess this could be solved if B2 allows negation. So I can say:
> `<target-os>not windows:<build>no `.
> Does this exist?
It is supported, but was broken until recently
https://github.com/boostorg/build/pull/594