GHCi :doc command doesn't work in ghc-9.4-alpha1
~ $ ghci-9.4
GHCi, version 9.4.0.20220501: https://www.haskell.org/ghc/ :? for help
ghci> import Data.Map
ghci> :doc insert
Can't find any documentation for Data.Map.Internal.
Try re-compiling with '-haddock'.
ghci> :doc head
Can't find any documentation for GHC.List.
Try re-compiling with '-haddock'.
Method of installation:
Via GHCup according to these instructions. The URL of the tarball is https://downloads.haskell.org/ghc/9.4.1-alpha1/ghc-9.4.0.20220501-x86_64-deb11-linux.tar.xz.