Annotation alias has unclear error with `class.together`

[samdphillips]

This produces expansion time error, ?: annotation static information needed before completed in: name

annot.macro 'E': 'Int || C || D'

class.together:
  class C(c :: List.of(E))
  class D(d :: E)

This works though

annot.macro 'E': 'Int || C || D'

class.together:
  class C(c :: List.of(Int || C || D))
  class D(d :: E)

[usaoc]

I see now the reported error is C: annotation static information needed before completed, so at least you know which annnotation is expanded too early. The actual way to make this program work is

annot.delayed_declare E

class.together:
  class C(c :: List.of(E))
  class D(d :: E)

annot.delayed_complete E: Int || C || D

so maybe it should suggest using annot.delayed_{declare,complete} to tie the knot?