vectordotdev/vector · error · syn::Error

component must have a name defined (e.g. `#[component_name("

Error message

component must have a name defined (e.g. `#[component_name("foobar")]`)

What it means

The component-name derive/attribute machinery in vector-config-macros requires every instrumented component type to declare exactly one name via `#[component_name("...")]`. After validating any attribute tokens, if none produced a usable name, the macro emits this compile error on the type's span. Without the constant NAME the generated docs and config schema cannot identify the component.

Source

Thrown at lib/vector-config-macros/src/component_name.rs:73

                errors.push(e);
                None
            }
        })
        .collect::<Vec<_>>();

    if !errors.is_empty() {
        let mut main_error = errors.remove(0);
        for error in errors.drain(..) {
            main_error.combine(error);
        }

        return main_error.into_compile_error().into();
    }

    // Any component names we have now have been validated, so we just need to check and make sure
    // we actually have one, and only one, and spit out the correct errors otherwise.
    if component_names.is_empty() {
        return Error::new(
            ident.span(),
            "component must have a name defined (e.g. `#[component_name(\"foobar\")]`)",
        )
        .into_compile_error()
        .into();
    }

    if component_names.len() > 1 {
        return Error::new(ident.span(), "component cannot have multiple names defined")
            .into_compile_error()
            .into();
    }

    let component_name = component_names.remove(0);

    // We have a single, valid component name, so let's actually spit out our derive.
    let (impl_generics, ty_generics, where_clause) = input.generics.split_for_impl();
    let derived = quote! {

View on GitHub (pinned to 3708c39b12)

Solutions

1. Add exactly one `#[component_name("your_component")]` attribute to the type carrying the derive.
2. Check spelling/placement — the attribute must sit on the same item the macro processes.
3. Copy the attribute block from a sibling component in the same directory as a template.

Example fix

// before
#[derive(ComponentName)]
struct MySinkConfig;

// after
#[component_name("my_sink")]
#[derive(ComponentName)]
struct MySinkConfig;

// The compiler enforces this at derive time; fix by adding the attribute:
// #[component_name("my_component")]
// #[derive(...)] struct MyConfig;

When it happens

Trigger: Applying the component-name derive (or the `#[configurable_component(...)]` family) to a type without attaching `#[component_name("my_component")]`, or with the attribute misspelled so it is not recognized.

Common situations: Contributors adding a new source/transform/sink who copy the derive list but drop the name attribute; typos like `#[component_names(...)]` or placing the attribute on the wrong item so it is not collected.

Related errors

• component cannot have multiple names defined
• {component_type}s must have a name specified (e.g. `{compone
• #[derive(NamedInternalEvent)] can only be used with structs
• expected a string literal for the {component_type} name (i.e
• component name must be non-empty

AI-assisted analysis of vectordotdev/vector@3708c39b12 (2026-08-20). Data as JSON: /api/errors/e2ce076aa3962342. Report an issue: GitHub.