% cabal list transformers --installed
    * transformers
        Synopsis: Concrete functor and monad transformers
        Default available version: 0.5.6.2
        Installed versions: 0.5.6.2
        License:  BSD3

    % cabal list transformers --installed -w ghc-8.10.1
    * transformers
        Synopsis: Concrete functor and monad transformers
        Default available version: 0.5.6.2
        Installed versions: 0.5.6.2
        License:  BSD3

    % cabal list transformers --installed -w ghc-7.6.3
    No matches found.

    % cabal list transformers --installed -w ghc-7.8.4
    * transformers
        Synopsis: Concrete functor and monad transformers
        Default available version: 0.5.6.2
        Installed versions: 0.3.0.0
        License:  BSD3