Qualified name required when defining type family instance in instance declaration
With these two modules, GHC gives the following error:
Bar.hs:3:30: Not in scope: type constructor or class `T'I have to use Foo.T in the instance definition. This is inconsistent with method definitions which must use unqualified names.
module Foo where
class C a where type T amodule Bar where
import qualified Foo
instance Foo.C Int where type T Int = IntTrac metadata
| Trac field | Value |
|---|---|
| Version | 6.9 |
| Type | Bug |
| TypeOfFailure | OtherFailure |
| Priority | normal |
| Resolution | Unresolved |
| Component | Compiler |
| Test case | |
| Differential revisions | |
| BlockedBy | |
| Related | |
| Blocking | |
| CC | |
| Operating system | Unknown |
| Architecture | Unknown |