The latest release (1.21.0) does not build under ghc 8.8.1, since it uses the old Monad.fail method (instead of MonadFail.fail):
[ 7 of 18] Compiling Language.Haskell.Exts.Fixity ( src/Language/Haskell/Exts/Fixity.hs, dist/build/Language/Haskell/Exts/Fixity.o )
src/Language/Haskell/Exts/Fixity.hs:72:25: error:
• Could not deduce (MonadFail m) arising from a use of ‘infFix’
from the context: Monad m
bound by the type signature for:
applyFixities :: forall (m :: * -> *).
Monad m =>
[Fixity] -> Exp SrcSpanInfo -> m (Exp SrcSpanInfo)
at src/Language/Haskell/Exts/Fixity.hs:72:3-15
The latest release (1.21.0) does not build under ghc 8.8.1, since it uses the old
Monad.fail
method (instead ofMonadFail.fail
):