DioxusLabs/dioxus · error · syn::Error

unexpected extra argument

Error message

unexpected extra argument

What it means

Error "unexpected extra argument" thrown in DioxusLabs/dioxus.

Source

Thrown at packages/fullstack-macro/src/lib.rs:1703

                    } else {
                        return Err(syn::Error::new(value.span(), "expected string literal"));
                    }
                }
            } else if lookahead.peek(LitStr) {
                if use_key_and_value {
                    return Err(syn::Error::new(
                        stream.span(),
                        "If you use keyword arguments (e.g., `name` = \
                         Something), then you can no longer use arguments \
                         without a keyword.",
                    ));
                }
                match arg_pos {
                    1 => return Err(lookahead.error()),
                    2 => prefix = Some(stream.parse()?),
                    3 => encoding = Some(stream.parse()?),
                    4 => fn_path = Some(stream.parse()?),
                    _ => return Err(syn::Error::new(stream.span(), "unexpected extra argument")),
                }
            } else {
                return Err(lookahead.error());
            }

            if !stream.is_empty() {
                stream.parse::<Token![,]>()?;
            }
        }

        // Now parse any remaining extractors (key: Type pattern)
        while !stream.is_empty() {
            if stream.peek(Ident) && stream.peek2(Token![:]) {
                server_args.push_value(stream.parse::<FnArg>()?);
                if stream.peek(Comma) {
                    server_args.push_punct(stream.parse::<Comma>()?);
                } else {
                    break;

View on GitHub (pinned to 393d190a80)

When it happens

Trigger: Thrown at packages/fullstack-macro/src/lib.rs:1703 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of DioxusLabs/dioxus@393d190a80 (2026-08-16). Data as JSON: /api/errors/05fa6872631e9cdc. Report an issue: GitHub.