clone macro fails to compile indicating trait bounds are not satisfied but I am not sure why it is required to be satisfied because all struct members are clonnable

[softstream-link]

I tried this code:

use std::sync::Arc;

trait Blah {}
struct IamBlah;
impl Blah for IamBlah {}

#[derive(Debug, Clone)]
struct ShouldBeClonable<N: Blah> {
    a: Arc<N>,
}

fn main() {
    let x = ShouldBeClonable { a: Arc::new(IamBlah) };
    let y = x.clone();
    println!("{:?}", y);
}

I expected to see this happen: I expect this to compile

At the same time this works if implemented manually

use std::sync::Arc;

trait Blah {}

#[derive(Debug)]
struct IamBlah;
impl Blah for IamBlah {}

// #[derive(Debug, Clone)]
#[derive(Debug)]
struct ShouldBeClonable<N: Blah> {
    a: Arc<N>,
}
impl<N: Blah> Clone for ShouldBeClonable<N> {
    fn clone(&self) -> Self {
        Self { a: self.a.clone() }
    }
}

fn main() {
    let x = ShouldBeClonable { a: Arc::new(IamBlah) };
    let y = x.clone();
    println!("{:?}", y);
}

Instead, this happened: I get a compiler error indicating

error[E0599]: the method `clone` exists for struct `ShouldBeClonable<IamBlah>`, but its trait bounds were not satisfied
  --> experimentation/examples/clone_gen.rs:14:15
   |
4  | struct IamBlah;
   | -------------- doesn't satisfy `IamBlah: Clone`
...
8  | struct ShouldBeClonable<N: Blah> {
   | --------------------------------
   | |
   | method `clone` not found for this struct
   | doesn't satisfy `ShouldBeClonable<IamBlah>: Clone`
...
14 |     let y = x.clone();
   |               ^^^^^ method cannot be called on `ShouldBeClonable<IamBlah>` due to unsatisfied trait bounds
   |
note: trait bound `IamBlah: Clone` was not satisfied
  --> experimentation/examples/clone_gen.rs:7:17
   |
7  | #[derive(Debug, Clone)]
   |                 ^^^^^ unsatisfied trait bound introduced in this `derive` macro
   = help: items from traits can only be used if the trait is implemented and in scope
   = note: the following trait defines an item `clone`, perhaps you need to implement it:
           candidate #1: `Clone`
help: consider annotating `IamBlah` with `#[derive(Clone)]`
   |
4  + #[derive(Clone)]
5  | struct IamBlah;
   |

For more information about this error, try `rustc --explain E0599`.

Meta

rustc --version --verbose:

rustc 1.75.0 (82e1608df 2023-12-21)
binary: rustc
commit-hash: 82e1608dfa6e0b5569232559e3d385fea5a93112
commit-date: 2023-12-21
host: aarch64-apple-darwin
release: 1.75.0
LLVM version: 17.0.6

Backtrace

n/a

[compiler-errors]

This issue has some explanation for why derive(Clone) is the way it is and some other cross-links for related discussion: #108894 (comment)

I'm gonna close this as a dupe.