Description
Related to changes from #1388 + #1390. Before the change in #1390 the tests on CI passed because they use cargo test --all --all-features, this would activate the futures-test/std feature while running the futures tests; but if you want to run just the futures tests locally with cargo test -p futures-preview they would fail because the futures-test/std feature was not activated. Removing default-features false from the futures-test dev-dependency in futures fixed this so that both ways of testing would work, but because of feature unification between dev and non-dev dependencies this results in the futures-core/std feature being force activated always.
I don't see any way to fix this with how features currently work in Cargo, but there's been no real movement on un-unifying the features of dependency types (rust-lang/cargo#4866).