risingwavelabs/risingwave · error

Missing prefix string argument

Error message

Missing prefix string argument

What it means

Compile-time error raised at the end of parse_args (invoked via try_prefix_all) when the serde prefix attribute was parsed but no prefix string argument was found among its arguments — i.e. the attribute was invoked without the required string literal that gets prepended to field names. It is a mandatory-argument guard; the derive cannot proceed without a prefix.

Solutions

1. Add the required string literal prefix to the attribute, e.g. `#[prefix_all("prefix_")]`
2. If mode was passed (e.g. `mode = "alias"`), still supply the prefix string argument alongside it

When it happens

Trigger: Thrown at src/common/proc_macro/src/serde_prefix_all.rs:112 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of risingwavelabs/risingwave@6469eb736d (2026-09-11). Data as JSON: /api/errors/abea66d6ebe61072. Report an issue: GitHub.

Appendix: source

Thrown at src/common/proc_macro/src/serde_prefix_all.rs:112

                            ));
                        }
                    },
                    _ => return Err(Error::new(lit.span(), "mode must be a string literal")),
                };

                mode = Some(parsed_mode);
            }
            NestedMeta::Meta(meta) => {
                return Err(Error::new(
                    meta.span(),
                    "Unsupported attribute argument, expected a string literal prefix or mode",
                ));
            }
        }
    }

    let (prefix, span) =
        prefix.ok_or_else(|| Error::new(Span::call_site(), "Missing prefix string argument"))?;
    Ok(ParsedArgs {
        prefix,
        prefix_span: span,
        mode: mode.unwrap_or(Mode::Rename),
    })
}

pub(crate) fn try_prefix_all(
    args: AttributeArgs,
    mut input: DeriveInput,
) -> syn::Result<TokenStream> {
    let ParsedArgs {
        prefix,
        prefix_span,
        mode,
    } = parse_args(args)?;

    match &mut input.data {

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