@escritorio-gustavo Could you take a quick peek at this?

As far as I can tell the CI ran cargo t --no-default-features only in the root directory, where the --no-default-features argument does nothing. So, possibly, default-features = false has been broken for a while. Oops!

Biggest change I've made here is to remove almost all of the #[cfg(feature = "serde-compat")] gates - I only kept them where we actually need them (e.g for printing the warning - we don't have the termcolor dependency without serde-compat).

In the other places, I used if cfg!(feature = "serde-compat") instead. That makes a lot of things, especially imports, easier.
As you can see in the CI run for the first commit, those were most of the issues - crate::attr::Serde was imported, but it was gated behind the feature flag.

Does this seem alright to you?

those were most of the issues - crate::attr::Serde was imported, but it was gated behind the feature flag.

Oops, sorry about that! Thankfully #290 hasn't been published yet as it was made after the release of version 8.1.0, so hopefully no one has been affected

Biggest change I've made here is to remove almost all of the #[cfg(feature = "serde-compat")] gates [...], I used if cfg!(feature = "serde-compat") instead.
[...]
Does this seem alright to you?

Sure! I'm fine with both

Ah, perfect! I thought you did those changes quite some time ago. Even better!