8.8.1-alpha2: fail is not a (visible) method of class Monad
Summary
utils/genprimopcode/ParserM.hs:45:5: error:
‘fail’ is not a (visible) method of class ‘Monad’
|
45 | fail err = ParserM $ \_ _ -> Left err
Steps to reproduce
Built 8.8.1-alpha1 with ghc 8.6.5 and installed it. Then tried to build it again with 8.8.1-alpha1 and got the above.
Expected behavior
GHC needs to be able to build itself. Solution is probably to add a MonadFail
instance for ParserM
.
Environment
- GHC version used: 8.8.1-alpha1 from source code tarball.
Optional:
- Operating System: Linux
- System Architecture: amd64