Conflicting typefamily instances not reported with polykinds
GHC fails to report conflicting instances for a open polykinded type family when the two resulting types have different kinds. I would expect conflicts to be detected regardless of the concrete kind of the result.
Minimal Example:
type family Bar a :: k
type instance Bar Int = Int
--type instance Bar Int = Bool -- Conflict detected
type instance Bar Int = [] -- Conflict NOT detectedTrac metadata
| Trac field | Value |
|---|---|
| Version | 7.8.3 |
| Type | Bug |
| TypeOfFailure | OtherFailure |
| Priority | normal |
| Resolution | Unresolved |
| Component | Compiler |
| Test case | |
| Differential revisions | |
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| Related | |
| Blocking | |
| CC | |
| Operating system | |
| Architecture |