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libraries/haskeline/System/Console/Haskeline/Backend/DumbTerm.hs:25:49:
Could not coerce from ‘StateT
Window (PosixT m) (StateT Window (PosixT m) a)’
to ‘StateT Window (PosixT m) (DumbTerm m a)’
because the third type argument of ‘StateT’ has role Nominal,
but the arguments ‘StateT Window (PosixT m) a’ and ‘DumbTerm m a’
differ
arising from the coercion of the method ‘GHC.Base.join’
from type ‘forall a.
StateT Window (PosixT m) (StateT Window (PosixT m) a)
-> StateT Window (PosixT m) a’
to type ‘forall a. DumbTerm m (DumbTerm m a) -> DumbTerm m a’
Possible fix:
use a standalone 'deriving instance' declaration,
so you can specify the instance context yourself
When deriving the instance for (Monad (DumbTerm m))
make[1]: *** [libraries/haskeline/dist-install/build/System/Console/Haskeline/Backend/DumbTerm.o] Error 1
make[1]: *** Waiting for unfinished jobs....
libraries/haskeline/System/Console/Haskeline/Backend/Terminfo.hs:107:37:
Could not coerce from ‘ReaderT
Actions
(ReaderT Terminal (StateT TermRows (StateT TermPos (PosixT m))))
(ReaderT
Actions
(ReaderT Terminal (StateT TermRows (StateT TermPos (PosixT m))))
a)’
to ‘ReaderT
Actions
(ReaderT Terminal (StateT TermRows (StateT TermPos (PosixT m))))
(Draw m a)’
because the third type argument of ‘ReaderT’ has role Nominal,
but the arguments
‘ReaderT
Actions
(ReaderT Terminal (StateT TermRows (StateT TermPos (PosixT m))))
a’
and ‘Draw m a’ differ
arising from the coercion of the method ‘join’
from type ‘forall a.
ReaderT
Actions
(ReaderT Terminal (StateT TermRows (StateT TermPos (PosixT m))))
(ReaderT
Actions
(ReaderT Terminal (StateT TermRows (StateT TermPos (PosixT m))))
a)
-> ReaderT
Actions
(ReaderT Terminal (StateT TermRows (StateT TermPos (PosixT m))))
a’
to type ‘forall a. Draw m (Draw m a) -> Draw m a’
Possible fix:
use a standalone 'deriving instance' declaration,
so you can specify the instance context yourself
When deriving the instance for (Monad (Draw m))
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