diesel-rs/diesel · error · syn::Error

Expected `require_order` but got

Error message

Expected `require_order` but got `{ident}`

What it means

Inside `#[sql_function]`, the `parse_require_order` helper only accepts the key `require_order = <bool>`. Any other identifier passed where `require_order` is expected produces this error naming what was actually found.

Solutions

1. Write the option exactly as `require_order = true` (or `= false`)
2. Fix any misspelling of `require_order`
3. Remove the extraneous token if it was not intended as an option

Example fix

// before
#[sql_function(require_ord = true)]
// after
#[sql_function(require_order = true)]

fn is_require_order_key(key: &str) -> bool { key == "require_order" }

fn is_require_order_key(key: &str) -> bool { key == "require_order" }

When it happens

Trigger: Calling the attr parser with an identifier other than `require_order` where the macro expects it — e.g. `require_ord = true`, `ordering = true`, or passing a key in the wrong position of the attribute list.

Common situations: Typos (`require_order` misspelled); assuming other ordering-related options exist; mixing option order so a value lands where a key is expected.

Understand the failure class

Background: "unknown output mode", "invalid value for flag", "expects true/false": fixing invalid flag value errors in CLI tools — this error's family across 24 libraries.

Related errors

• expected attribute `name` help: the correct format looks…
• unknown attribute, expected
• expect `skip_zero_argument_variant`
• , the correct format is `#[variadic(last_arguments = 3)]`…
• , the correct format is `#[variadic(3)]

AI-assisted analysis of diesel-rs/diesel@6fa6ed01b2 (2026-09-07). Data as JSON: /api/errors/0bcf3ff19794bf36. Report an issue: GitHub.

Appendix: source

Thrown at diesel_derives/src/sql_function.rs:1920

            SqlFunctionAttribute::Restriction {
                restriction: BackendRestriction::None,
                ..
            } => {
                unreachable!("We do not construct that")
            }
            SqlFunctionAttribute::Other(attribute) => attribute.span(),
        }
    }
}

fn parse_require_order(input: &syn::parse::ParseBuffer<'_>) -> Result<bool> {
    let ident = input.parse::<Ident>()?;
    if ident == "require_order" {
        let _ = input.parse::<Token![=]>()?;
        let value = input.parse::<LitBool>()?;
        Ok(value.value)
    } else {
        Err(syn::Error::new(
            ident.span(),
            format!("Expected `require_order` but got `{ident}`"),
        ))
    }
}

impl SqlFunctionAttribute {
    fn parse_attr(
        name: Ident,
        input: &syn::parse::ParseBuffer<'_>,
        attr: Attribute,
        attribute_span: proc_macro2::Span,
    ) -> Result<AttributeSpanWrapper<Self>> {
        // rustc doesn't resolve cfg attrs for us :(
        // This is hacky, but mostly for internal use
        if name == "cfg_attr" {
            let ident = input.parse::<Ident>()?;
            if ident != "feature" {

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