[Haskell-cafe] Haddock 2.8.1 and alex 3.0.1

[cwr at netcom.co.uk]

Building haddock 2.8.1 with alex 3.0.1 I get the error message:

[ 7 of 33] Compiling Haddock.Lex      ( dist/build/Haddock/Lex.hs,  
dist/build/Haddock/Lex.o )

src/Haddock/Lex.x:150:17:
     Couldn't match expected type `AlexInput'
            against inferred type `(t, t1, t2)'
     In the first argument of `alexScan', namely `inp'
     In the expression: alexScan inp sc
     In the expression:
         case alexScan inp sc of {
           AlexEOF -> []
           AlexError _ -> error "lexical error"
           AlexSkip inp' _ -> go inp' sc
           AlexToken (inp'@(pos', _, _)) len act
             ->

Haddock 2.8.1 builds correctly (or at least completely) with alex 2.3.5
I'm not sure if this is a bug or a feature - if it's a feature, then the
dependencies for haddock 2.8.1 need updating.

Will