$ cabal build -w ghc-9.4.0.20220501
...
[15 of 24] Compiling Control.Monad.Writer.Class
Control/Monad/Writer/Class.hs:201:3: warning: [-Wredundant-constraints]
• Redundant constraint: Monoid w
• In the instance declaration for ‘MonadWriter w (AccumT w m)’
|
201 | ( Monoid w
| ^^^^^^^^^^...