Failed to find trait implementation

[sirasistant]

Aim

Implement an automatically derivable serialize trait.
I have outputted what the derive is generating, and it's not finding a trait and I don't know why:

pub trait Deserialize<let N: u32> {
    fn deserialize(serialized: [Field; N]) -> Self;
}
impl Deserialize<1> for Field {
    fn deserialize(serialized: [Field; 1]) -> Self {
        serialized[0]
    }
}
impl Deserialize<1> for u32 {
    fn deserialize(serialized: [Field; 1]) -> Self {
        serialized[0] as u32
    }
}
impl<T, let K: u32> Deserialize<K + 1> for Option<T>
where
    T: Deserialize<K>,
{
    fn deserialize(serialized: [Field; K + 1]) -> Self {
        let is_some = serialized[0] == 1;
        if is_some {
            let mut deserialized = [0; K];
            for i in 0..K {
                deserialized[i] = serialized[i + 1];
            }
            Self::some(T::deserialize(deserialized))
        } else {
            Self::none()
        }
    }
}
impl<T, let N: u32, let K: u32> Deserialize<K * N> for [T; N]
where
    T: Deserialize<K>,
{
    fn deserialize(serialized: [Field; K * N]) -> Self {
        let mut result = [std::mem::zeroed(); N];
        let mut offset = 0;
        for i in 0..N {
            let mut deserialized = [0; K];
            for j in 0..K {
                deserialized[j] = serialized[offset + j];
            }
            result[i] = T::deserialize(deserialized);
            offset += K;
        }
        result
    }
}
#[derive(Eq)]
struct Bar {
    a: [Field; 1],
    b: Option<Field>,
}

// Autogenerated implementation
impl<let a_serialized_length: u32, let b_serialized_length: u32> Deserialize<a_serialized_length + b_serialized_length> for Bar
where
    [Field; 1]: Deserialize<a_serialized_length>,
    Option<Field>: Deserialize<b_serialized_length>,
{
    fn deserialize(serialized: [Field; a_serialized_length + b_serialized_length]) -> Self {
        let mut offset = 0;
        let mut a_serialized = [0; a_serialized_length];
        for i in 0..a_serialized_length {
            a_serialized[i] = serialized[offset + i];
        }
        offset += a_serialized_length;
        let a = Deserialize::deserialize(a_serialized);
        let mut b_serialized = [0; b_serialized_length];
        for i in 0..b_serialized_length {
            b_serialized[i] = serialized[offset + i];
        }
        offset += b_serialized_length;
        let b = Deserialize::deserialize(b_serialized);
        Self { a, b }
    }
}


fn main() {
    let bar_deserialized = Bar::deserialize([0; 3]);
}

Expected Behavior

I think the above should compile

Bug

error: No matching impl found for `[Field; 1]: Deserialize<(3 - _)>`
    ┌─ src/main.nr:288:28
    │
288 │     let bar_deserialized = Bar::deserialize([0; 3]);
    │                            ---------------- No impl for `[Field; 1]: Deserialize<(3 - _)>`
    │

To Reproduce

Workaround

None

Workaround Description

No response

Additional Context

No response

Project Impact

None

Blocker Context

No response

Nargo Version

No response

NoirJS Version

No response

Proving Backend Tooling & Version

No response

Would you like to submit a PR for this Issue?

None

Support Needs

No response

[asterite]

It's interesting that if main is this:

    let bar_deserialized: Bar = Deserialize::deserialize([0; 3]);

then it still doesn't compile, but if you try to compile it multiple times the compiler will give one of two different errors (so there's a bit of non-determinism here, which is very strange!)

[TomAFrench]

there's a bit of non-determinism here

arggggggghhhhhhhhhh