ANNOUNCE: GHC version 6.8.2

[Judah Jacobson]

On Dec 17, 2007 5:58 PM, Manuel M T Chakravarty <chak at cse.unsw.edu.au> wrote:
> Ian Lynagh:
> > On Mon, Dec 17, 2007 at 12:53:32PM +1100, Manuel M T Chakravarty
> > wrote:
> >
> >> Actually, I think, we should use the gmp/ in the ghc repo by default
> >
> > If you want to use it when building a bindist that might be used on
> > other computers you shold be able to set
> >    HaveLibGmp = NO
> >    HaveFrameworkGMP = NO
> > in mk/build.mk, although I'm not sure I've ever tried it.
> >
> > The disadvantages of using it are it might be out of date (we had some
> > Windows segfaults a while ago that were fixed by updating the in-tree
> > gmp) and wasted space.
>
> Sure we waste some space, but the alternative is worse.  Programs
> compiled with GHC will essentially not run on any computer, but the
> one where they were compiled.  For example, the number of Macs with
> gmp installed is minuscule.  The default should be to build programs
> that run everywhere with minimal hassle (not programs that save some
> space, but are unusable on most computers).

My understanding was that one major reason to dynamically link against
GMP is to satisfy the LGPL, not just to save disk space.  I found a
couple old but relevant posts by Wolfgang Thaller, who originally
created HaskellSupport.framework (now GMP.framework):

http://www.haskell.org/pipermail/glasgow-haskell-users/2002-June/003494.html
http://www.haskell.org/pipermail/cvs-ghc/2005-March/023769.html

The gist of those posts is the following:
- Statically linking against GMP puts extra license requirements on
any ghc-compiled program; thus, dynamic linking is preferable.
- On OS X, installing new frameworks is very easy (just drag-and-drop
the framework into ~/Library/Frameworks or /Library/Frameworks; the
former doesn't even need admin privileges).  This doesn't seem like
much to ask of users.

Best,
-Judah