Migration issue when cyclic dependency is altered

• EdgeDB Version: 1-beta.2

Steps to Reproduce:

1. Apply the following schema:

module default {
    type Article {
        required property deleted := (EXISTS (.<element[IS default::DeletionRecord]));
    };
    type Category {
        required property deleted := (EXISTS (.<element[IS default::DeletionRecord]));
    };
    type DeletionRecord {
        required link element -> (default::Article | default::Category) {
            on target delete  delete source;
            constraint std::exclusive;
        };
    };
};

1. Change to:

module default {
    abstract type Removable {
        property deleted := EXISTS(.<element[IS DeletionRecord]);
    }
    type Article extending Removable {
    };
    type Category extending Removable {
    };
    type DeletionRecord {
        required link element -> Removable {
            on target delete delete source;
            constraint std::exclusive;
        };
    };
};

1. Get the following error on create-migration:

did you create object type 'default::Removable'? [y,n,l,c,b,s,q,?]
y
error: 'default::Removable.<element' does not resolve to any known path
  ┌─ query:2:41
  │
2 │     CREATE PROPERTY deleted := (EXISTS (.<element[IS default::DeletionRecord]));
  │                                         ^^^^^^^^^ error

Rolling back last operation...
did you create object type 'default::Removable'? [y,n,l,c,b,s,q,?]

On the other hand, schema from (2) works fine if applied from scratch

[elprans]

Can we rephrase error to something like

We prohibit mixing non-computables with computables as well, not just different computables, but I agree that the error message needs clarification. I’d actually specialize the message to each prohibited combination (i.e. computable and non-computable and computable/computable).

\cc @vpetrovykh

[elprans]

Is the limitation fundamental or temporary

Temporary, until the compiler learns to actually produce correct queries for polymorphic computables.