Closed Bodigrim closed 1 year ago
Starting from mtl-2.3 liftM is no longer re-exported from Control.Monad by Control.Monad.Writer.Strict. A simple backward-compatible fix is to replace liftM with fmap.
mtl-2.3
liftM
Control.Monad
Control.Monad.Writer.Strict
fmap
Thanks!
Did I target the wrong branch? Should it be ghc-head instead of main?
ghc-head
main
Starting from
mtl-2.3
liftM
is no longer re-exported fromControl.Monad
byControl.Monad.Writer.Strict
. A simple backward-compatible fix is to replaceliftM
withfmap
.