merge precondition message: Nested decl alias

[aryairani]

Nested decl alias

A decl cannot be aliased within the namespace of another of its aliased.

Alice's branch:

structural type A = B Nat | C Nat Nat
structural type A.inner.X = Y Nat | Z Nat Nat

project/alice> names A

  Type
  Hash:  #65mdg7015r
  Names: A A.inner.X
  
  Tip: Use `names.global` to see more results.

Bob's branch:

bob : Nat
bob = 100

project/alice> merge /bob

  On project/alice, the type A.inner.X is an alias of A. Type
  aliases cannot be nested. Please make them disjoint before
  merging.

---

Maybe:

On project/alice, the type A.inner.X is an alias of A. I'm not able to perform a merge when a type exists nested under an alias of itself. Please separate them or delete one copy, and then try merging again.