[TypeApplications] GHC internal error
Toying around, got
GHCi, version 8.1.20160503: http://www.haskell.org/ghc/ :? for help
[1 of 1] Compiling Main ( /tmp/CatFail.hs, interpreted )
/tmp/CatFail.hs:55:26: error:
• GHC internal error: ‘a’ is not in scope during type checking, but it passed the renamer
tcl_env of environment: [a1Ej :-> Type variable ‘i’ = i,
a1Ek :-> Type variable ‘p’ = p, a1Et :-> Type variable ‘a’ = a,
a1Eu :-> Type variable ‘b’ = b]
• In the first argument of ‘Vacuous’, namely ‘a’
In the type ‘Vacuous a’
In the expression: Dict @(Vacuous a)
/tmp/CatFail.hs:66:10: error:
• Couldn't match type ‘Fun p q’ with ‘Vacuous’
arising from a use of ‘Main.$dmsrc’
• In the expression: Main.$dmsrc
In an equation for ‘src’: src = Main.$dmsrc
In the instance declaration for ‘Category (Nat p q)’
• Relevant bindings include
src :: Nat p q a b -> Dict (Ob (Nat p q) a)
(bound at /tmp/CatFail.hs:66:10)
Failed, modules loaded: none.Trac metadata
| Trac field | Value |
|---|---|
| Version | 8.1 |
| Type | Bug |
| TypeOfFailure | OtherFailure |
| Priority | normal |
| Resolution | Unresolved |
| Component | Compiler |
| Test case | |
| Differential revisions | |
| BlockedBy | |
| Related | |
| Blocking | |
| CC | |
| Operating system | |
| Architecture |