GHC internal error: `a' is not in scope during type checking, but it passed the renamer
In the attached code the following lines give an internal GHC error. At least this should not happen. I also think this is valid code. Removing either type annotation makes this code compile.
bug :: WrappedR Int -> SomeFunction
bug (Wrap node) = case node of
(Memo' (emptyT :: t a b) memoize (Var m) :: R' a b Int) -> -- also breaks
/Users/alessandro/Documents/Uni/thesis/test/bug-tvar-passed-renamer.hs:14:104:
GHC internal error: `a' is not in scope during type checking, but it passed the renamer
tcl_env of environment: [(am4,
Identifier[node::R' a b Int, <NotTopLevel>, 1]),
(rgs,
Identifier[bug::WrappedR Int -> SomeFunction, <NotTopLevel>, 1])]
In the type `R' a b Int'
In a pattern type signature: R' a b Int
In the pattern:
Memo' (emptyT :: t a b)
(memoize :: MVar (t a b) -> (a -> b) -> a -> b)
(Var m :: R' a b Int) :: R' a b Int
Trac metadata
Trac field | Value |
---|---|
Version | 7.6.2 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | |
Architecture |