Integrating editline with ghc

[Manuel M T Chakravarty]

Alex Young:
> Yitzchak Gale wrote:
>> Isaac Dupree wrote:
>>> GHC is in no legal trouble whatsoever... only if proprietary Haskell
>>> code uses the readline library and doesn't switch to using the  
>>> editline
>>> backend.
>> Agreed. I didn't mean that GHC itself was ever in any
>> legal trouble. But as a compiler, it must be possible for
>> users to compile with it without getting into legal trouble.
>
> Yes.  I'm still learning Haskell, and it's my intention to use GHC  
> to produce commercial plugins for an application on Windows (and  
> possibly OS X, haven't decided yet).  This whole discussion makes me  
> worry - not because I have any intention to break any licences, but  
> because I might do so by accident.  At this point in my learning,  
> I've got no idea what will cause "problem packages" (problems from  
> my point of view being ones that cause a phone call to a lawyer) to  
> be linked in to my binaries.  It would be enormously helpful if  
> there was a wiki page somewhere that said "To use GHC/mingw as a  
> compiler for commercial software, it's likely you want to avoid  
> these modules and command-line flags" or alternatively "To guarantee  
> that no LGPL or GPL libraries are linked, use these flags".
>
> The last thing I want is to cause myself extra work when someone  
> chucks my plugin through a hex editor, sees a whole load of GMP  
> symbols (for example) and demands some form of compliance that  
> commercially I'd rather avoid.

The Haskell package system Cabal has a package description format that  
includes an entry stating the packages license.  You can browse  
packages at

   http://hackage.haskell.org/packages/hackage.html

and the package entries include the license field.  For example, the  
entry for readline

   http://hackage.haskell.org/cgi-bin/hackage-scripts/package/readline-1.0.1.0

says it is GPL'ed - ie, you may not link it into proprietary code.

I agree that a wiki page explaining this and the situation with static  
versus dynamic linking of LGPL'ed code would be helpful.

Manuel