- Use separate jobs instead of `matrix`. The Github Actions matrix is very cursed, especially if you use `include`. We don't have that many combinations, IMO doing separate jobs is way more straightforward and only slightly more verbose.
- `embedded-hal` needs `rust-version = 1.60` because it uses `dep:`.
Fixes#538
`feature()` is only allowed on Nightly, it's completely disallowed on stable and beta
even for already-stabilized features. So, we autodetect whether the user is using nightly
and conditionally use `feature()`. This allows the crates to Just Work on current 1.75 beta
and will also Just Work when 1.75 stable is out.
Keeping `feature()` is desirable to keep support for:
- Espressif's xtensa rustc fork. (they build from the stable branch but enable use of `feature()`, so latest xtensa rustc still requires `feature()`)
- Users of older nightlies
Once xtensa rust 1.75 is out, we can remove this (upstream nightlies that require `feature()` will be quite old by then, so dropping support for them should be OK).
I decided to not use already-made crates like `rustversion` to do this because they're quite big and do way more than what we need, so I felt badd adding another dep. The code is inspired from `rustversion`'s build.rs.
If we want to release `embedded-io` 1.0 and the adapters live there, we can't make any
breaking changes to them after release. Putting them in a separate crate
allows doing breaking changes without breaking everyone using the IO traits.
