Resolving dependencies...
Downloading clevercss-0.2...
Configuring clevercss-0.2...
Building clevercss-0.2...
Preprocessing library clevercss-0.2...
[1 of 2] Compiling Text.CSS.CleverCSSUtil ( Text/CSS/CleverCSSUtil.hs, dist/build/Text/CSS/CleverCSSUtil.o )
[2 of 2] Compiling Text.CSS.CleverCSS ( Text/CSS/CleverCSS.hs, dist/build/Text/CSS/CleverCSS.o )

Text/CSS/CleverCSS.hs:30:10:
    Illegal instance declaration for `Applicative (GenParser toc st)'
      (All instance types must be of the form (T a1 ... an)
       where a1 ... an are *distinct type variables*,
       and each type variable appears at most once in the instance head.
       Use -XFlexibleInstances if you want to disable this.)
    In the instance declaration for `Applicative (GenParser toc st)'
Failed to install clevercss-0.2
cabal: Error: some packages failed to install:
clevercss-0.2 failed during the building phase. The exception was:
ExitFailure 1