Derive macros are not hygienic enough

[ADD-SP]

The following code is unable to compile, this issue was found while testing my own project.

According to proc-macro-workshop:

Generally all macros (procedural as well as macro_rules) designed to be used
by other people should refer to every single thing in their expanded code
through an absolute path, such as std::result::Result.

// empty module has nothing and be used to redefine symbols
mod empty {}

// redefine the prelude `::std`
use empty as std;

// redefine the dependency `::prometheus_client`
use empty as prometheus_client;

// redefine the prelude `::core::result::Result`.
type Result = ();

enum TResult {
    Ok,
    Err,
}

// redefine the prelude `::core::result::Result::Ok/Err`.
use TResult::Ok;
use TResult::Err;

#[derive(Debug, Clone, PartialEq, Eq, Hash, ::prometheus_client::encoding::EncodeLabelSet)]
struct LableSet {
    a: String,
    b: LabelEnum,
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, ::prometheus_client::encoding::EncodeLabelValue)]
enum LabelEnum {
    A,
    B,
}

fn main() {}