cabal install leksah: unable to resolve dependencies

[allancth]

Hi. I am trying to install leksah but got the following error when trying to run 'cabal install leksah':

# cabal install leksah

Resolving dependencies...

cabal: Could not resolve dependencies:

trying: leksah-server-0.16.3.0 (dependency of leksah-0.16.2.2)

next goal: haddock-api (dependency of leksah-server-0.16.3.0)

rejecting: haddock-api-2.17.4, haddock-api-2.17.3.1, haddock-api-2.17.3,

haddock-api-2.17.2, haddock-api-2.16.1, haddock-api-2.16.0,

haddock-api-2.15.0.2, haddock-api-2.15.0.1, haddock-api-2.15.0 (conflict:

leksah-server => haddock-api>=2.18.1 && <2.19)

Dependency tree exhaustively searched.

Any idea how I can resolve this? Thanks in advance.

More info:

# cabal info base

* base             (library)

    Synopsis:      Basic libraries

    Versions available: 3.0.3.1, 3.0.3.2, 4.7.0.2, 4.8.0.0, 4.8.1.0, 4.8.2.0,

                        4.9.0.0, 4.9.1.0, 4.10.0.0 (and 15 others)

    Versions installed: 4.10.0.0

    Homepage:      [ Not specified ]

    Bug reports:   http://ghc.haskell.org/trac/ghc/newticket?component=libraries/base

    Description:   This package contains the "Prelude" and its support

                   libraries, and a large collection of useful libraries ranging

                   from data structures to parsing combinators and debugging

                   utilities.

    Category:      Prelude

    License:       BSD3

    Maintainer:    ***Removed to prevent email scrapping***

    Source repo:   http://git.haskell.org/ghc.git

    Flags:         integer-simple, integer-gmp

    Dependencies:  rts ==1.0.*, ghc-prim ==0.5.*,

                   invalid-cabal-flag-settings <0,

                   integer-simple >=0.1.1 && <0.2, integer-gmp ==1.0.*

    Documentation: /opt/programs/ghc-8.2.1/share/doc/ghc-8.2.1/html/libraries/base-4.10.0.0

# cabal info haddock

* haddock          (program)

    Synopsis:      A documentation-generation tool for Haskell libraries

    Versions available: 0.8, 0.9, 2.15.0.1, 2.15.0.2, 2.16.0, 2.16.1, 2.17.2,

                        2.17.4, 2.17.5 (and 33 others)

    Versions installed: [ Unknown ]

    Homepage:      http://www.haskell.org/haddock/

    Bug reports:   https://github.com/haskell/haddock/issues

    Description:   Haddock is a documentation-generation tool for Haskell

                   libraries

    Category:      Documentation

    License:       BSD3

    Author:        Simon Marlow, David Waern

    Maintainer:    ***Removed to prevent email scrapping***

    Source repo:   https://github.com/haskell/haddock.git

    Executables:   haddock

    Flags:         in-ghc-tree

    Dependencies:  haddock-api ==2.17.4, transformers -any, bytestring -any,

                   ghc >=7.11 && <8.1, ghc-boot -any, Cabal >=1.10,

                   xhtml ==3000.2.*, array -any, deepseq -any, containers -any,

                   directory -any, filepath -any, base ==4.9.*,

                   haddock-test ==0.0.1, filepath -any, base -any,

                   haddock-test ==0.0.1, filepath -any, base -any,

                   haddock-test ==0.0.1, filepath -any, base -any,

                   haddock-test ==0.0.1, filepath -any, base -any, hspec -any,

                   base -any

    Cached:        No