bevyengine/bevy · error · syn::Error

`#[type_name = "..."]` must be a string literal

Error message

`#[type_name = "..."]` must be a string literal

What it means

Compile-time error from the Reflect derive macro (from_input): the #[type_name = "..."] attribute was given something other than a string literal. Rewrite the attribute value as an ordinary string literal.

Source

Thrown at crates/bevy_reflect/derive/src/derive_data.rs:234

                    else {
                        return Err(syn::Error::new(
                            pair.span(),
                            format_args!("`#[{TYPE_PATH_ATTRIBUTE_NAME} = \"...\"]` must be a string literal"),
                        ));
                    };

                    custom_path = Some(syn::parse::Parser::parse_str(
                        parse_path_no_leading_colon,
                        &lit.value(),
                    )?);
                }
                Meta::NameValue(pair) if pair.path.is_ident(TYPE_NAME_ATTRIBUTE_NAME) => {
                    let syn::Expr::Lit(syn::ExprLit {
                        lit: syn::Lit::Str(lit),
                        ..
                    }) = &pair.value
                    else {
                        return Err(syn::Error::new(
                            pair.span(),
                            format_args!("`#[{TYPE_NAME_ATTRIBUTE_NAME} = \"...\"]` must be a string literal"),
                        ));
                    };

                    custom_type_name = Some(parse_str(&lit.value())?);
                }
                #[cfg(feature = "reflect_documentation")]
                Meta::NameValue(pair) if pair.path.is_ident("doc") => {
                    if let syn::Expr::Lit(syn::ExprLit {
                        lit: syn::Lit::Str(lit),
                        ..
                    }) = &pair.value
                    {
                        doc.push(lit.value());
                    }
                }
                _ => continue,

View on GitHub (pinned to 396ca72708)

Solutions

1. Change the #[type_name] attribute value to a string literal

When it happens

Trigger: Thrown at crates/bevy_reflect/derive/src/derive_data.rs:234 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of bevyengine/bevy@396ca72708 (2026-08-20). Data as JSON: /api/errors/f1d920ec68cbffb7. Report an issue: GitHub.