Bug#867791: haskell-yi-language FTBFS: error: Couldn't match expected type with actual type

[Adrian Bunk]

Source: haskell-yi-language
Version: 0.2.1-3
Severity: serious
Tags: buster sid

https://buildd.debian.org/status/package.php?p=haskell-yi-language&suite=sid

...
[ 9 of 32] Compiling Yi.Lexer.Abella  ( dist-ghc/build/Yi/Lexer/Abella.hs, dist-ghc/build/Yi/Lexer/Abella.o )

src/Yi/Lexer/common.hsinc:24:34-48: error:
    * Couldn't match expected type `[(Yi.Buffer.Basic.Point, Char)]
                                    -> HlState -> (t1, t)'
                  with actual type `Int'
    * The function `act' is applied to two arguments,
      but its type `Int' has none
      In the expression: act chunk state
      In a pattern binding: (state', tokValue) = act chunk state
    * Relevant bindings include
        state' :: t1 (bound at src/Yi/Lexer/common.hsinc:24:14)
        tokValue :: t (bound at src/Yi/Lexer/common.hsinc:24:22)
/usr/share/cdbs/1/class/hlibrary.mk:147: recipe for target 'build-ghc-stamp' failed
make: *** [build-ghc-stamp] Error 1