facebook/relay · error

Unexpected RelayResolver

Error message

Unexpected RelayResolver

What it means

Internal invariant panic in write_constant_value: a Primitive::RelayResolverModel (a resolver reference) was passed where only printable constant primitives are allowed. Resolver references must be handled by dedicated printer paths, not constant printing.

Solutions

1. Ensure resolvers are referenced only from fields/exports, not as literal constant values
2. Check resolver @exportable/@RelayResolver usage so model references are routed through export paths
3. File a Relay compiler bug with a minimal repro — this branch should be unreachable in valid schemas

// Resolve RelayResolverModel references to their export/field value before printing
let resolved = match primitive {
    Primitive::RelayResolverModel { .. } => resolve_resolver_reference(primitive)?,
    other => other,
};
write_constant_value(&resolved);

fn is_literal_primitive(p: &Primitive) -> bool {
    !matches!(p, Primitive::RelayResolverModel { .. })
}

// pre-validate; a panic here is a compiler bug, capture with a repro and report upstream

When it happens

Trigger: write_argument_value or write_constant_value receives Primitive::RelayResolverModel — a Relay resolver model value reaching the constant/argument printing branch.

Common situations: A resolver whose return/argument type is another resolver, or a mis-wired resolver schema, causing the codegen printer to treat the resolver reference as a literal.

Related errors

• Expected to have a reader operation for
• Unexpected DynamicImport
• Expected at least one of an @updatable reader AST, or…
• Expected to have a typegen operation for
• Expected a key

AI-assisted analysis of facebook/relay@668b1b85e0 (2026-09-02). Data as JSON: /api/errors/2a28cfe727698a1e. Report an issue: GitHub.

Appendix: source

Thrown at compiler/crates/relay-codegen/src/printer.rs:937

                        f.pop();
                    }
                    f.push('}');
                    Ok(())
                }
            }
        }
        Primitive::Null | Primitive::SkippableNull => {
            f.push_str("null");
            Ok(())
        }
        Primitive::StorageKey(_, _) => panic!("Unexpected StorageKey"),
        Primitive::RawString(_) => panic!("Unexpected RawString"),
        Primitive::GraphQLModuleDependency(_) => panic!("Unexpected GraphQLModuleDependency"),
        Primitive::JSModuleDependency { .. } => panic!("Unexpected JSModuleDependency"),
        Primitive::ResolverModuleReference { .. } => panic!("Unexpected ResolverModuleReference"),
        Primitive::PropertyAccessor(_) => panic!("Unexpected PropertyAccessor"),
        Primitive::DynamicImport { .. } => panic!("Unexpected DynamicImport"),
        Primitive::RelayResolverModel { .. } => panic!("Unexpected RelayResolver"),
    }
}

View on GitHub (pinned to 668b1b85e0)