/a.ts(4,17): error TS2456: Type alias 'T' circularly references itself.
/b.ts(4,17): error TS2456: Type alias 'T' circularly references itself.


==== /a.ts (1 errors) ====
    import type { ns2 } from './b';
    export namespace ns1 {
      export namespace nested {
        export type T = ns2.nested.T;
                    ~
!!! error TS2456: Type alias 'T' circularly references itself.
      }
    }
    
==== /b.ts (1 errors) ====
    import type { ns1 } from './a';
    export namespace ns2 {
      export namespace nested {
        export type T = ns1.nested.T;
                    ~
!!! error TS2456: Type alias 'T' circularly references itself.
      }
    }
    