[Nix-dev] Re: setup-new and propagatedBuildInputs, sourcing setup-new multiple times ?

[Marc Weber]

On Tue, Nov 04, 2008 at 02:54:40PM +0100, Ludovic Courtès wrote:
> Hi,
> 
> Marc Weber <marco-oweber at gmx.de> writes:
> 
> > Am I correct that if multiple dependencies have a store path in
> > propagatedBuildInputs that /nix-support/setup-hook will be sourced
> > multiple times?
> >
> > Do we want this? I mean if you have PYTHONPATH=PATH1:PATH1:PATH1 it will
> > only make everything slightly slower but I can't see any benefits?
> 
> `setup-hook' is only used by the build daemon anyway, i.e., not at
> run-time once applications are installed, so I'd say it doesn't matter
> that much to have duplicates in the path.

We've had quite some discussion about what would be best to install a
complier / interpreter and its libs.
Examples:
  python
  ghc
  perl
  (C/ C++)

At least for ghc (and the new python implementation) I've just added all
libs to an env var and I also do export that while wrapping the final
compiler/ interpreter executable. Sure it doesn't matter if you have 10
libs.. But think about hackage or python or perl.. There are 100 libs.
And if those have the same dependencies .. They really will sum up.

Anyway I think that's something which can be added to stdenv-updates ...

When I come to that point I'll propose a patch.

cu
Marc Weber