[GHC] #3121: readline package does not respect Cabal --extra-{include, lib}-dirs flags

[GHC]

#3121: readline package does not respect Cabal --extra-{include,lib}-dirs flags
-----------------------------+----------------------------------------------
Reporter:  duncan            |          Owner:                   
    Type:  bug               |         Status:  new              
Priority:  normal            |      Component:  libraries (other)
 Version:  6.10.1            |       Severity:  normal           
Keywords:                    |       Testcase:                   
      Os:  Unknown/Multiple  |   Architecture:  Unknown/Multiple 
-----------------------------+----------------------------------------------
 The readline package still uses a `./configure` script. It has flags to
 set extra library and include dirs to search. These are needed by OSX
 users.

 The `./configure` script takes the flags:
 {{{
 --with-readline-includes=
 --with-readline-libraries=
 }}}

 However when an end user installs the package via Cabal, (either `runghc
 Setup` or `cabal`) they use the Cabal flags:

 {{{
 --extra-include-dirs=
 --extra-lib-dirs=
 }}}

 The problem is that the two sets of flags are not connected at all. If the
 configure script needs to know these directories then the Setup.hs for the
 package should pass them through. Users are not expected to know the per-
 package configure flags, especially when we already have suitable generic
 flags for the same purpose.

 The end result is that OSX users cannot install readline. Eg, today
 someone complained:

 {{{
 hm, I have installed libreadline from mac ports and I have
 told cabal to look for it in --extra-include-dirs
 --extra-lib-dirs I also have installed the GNU.framework for
 mac but it still fails...any suggestions?
 }}}

 This problem actually applies to most bindings packages that use configure
 scripts. See also [http://hackage.haskell.org/trac/hackage/ticket/458 this
 Cabal ticket] about similar mismatches with configure scripts.

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/3121>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler