Suggestion: Clearer schemagen error messages

Using the schema:

type ContactMethod { 
    id:     ID
    name:   String
    method_type: ContactMethodType
    method: ContactMethodValue
}
type Query { 
    getContactById(id: ID) : Contact
    getContactsByName(search: String) : [Contact]
    #getContactsByContactMethod(search: String) : [Contact]
    getContactsByContactMethod(search: ContactMethod) : [Contact]
}

I get the error message below when building:

Generating graphqllib GraphQL schema
Invalid argument type: ContactMethod line: 69 column: 32
CMake Error at C:/repos/cpp/appserver/x64-windows/vcpkg_installed/x64-windows/share/cppgraphqlgen/cppgraphqlgen-update-schema-files.cmake:40 (message):
Schema generation failed!

I modify this as follows and it works - perhaps it could point out it should be an input type if not a built-in?

type ContactMethod { 
    id:     ID
    name:   String
    method_type: ContactMethodType
    method: ContactMethodValue
}
input ContactMethodQueryInput { 
    name:   String
    method_type: ContactMethodType
}
type Query { 
    getContactById(id: ID) : Contact
    getContactsByName(search: String) : [Contact]
    #getContactsByContactMethod(search: String) : [Contact]
    getContactsByContactMethod(search: ContactMethodQueryInput) : [Contact]
}

Yeah, I'm pretty rusty at GraphQL - this took longer for me to find that I was happy with. :)

Start with the schema-generation entry point referenced in cppgraphqlgen-update-schema-files.cmake at line 40, then reproduce the shown schema-generation failure. The completed change should make an invalid object type used as an argument explain that an input type is required, while preserving the existing failure behavior.