[Nix-dev] Darwin support (was: Reverting simons change on perl r17618)

[Peter Simons]

Lluís Batlle wrote:

 > I reverted the change simons did on perl, because it caused a major
 > stdenv rebuild.

well, that patch is supposed to fix stdenv on Darwin so that the
platform can build packages depending on SWIG -- like Subversion, Git,
etc. The re-build on Linux was due to the fact that the Perl builder
script had to be modified to accomplish that.

I guess I could have duplicated the builder script instead, applied the
changes to the new one, say builder-darwin.sh, and then select builders
in Nix by means of stdenv.system. This construct would achieve the same
fix without causing a re-build on other platforms.

However, introducing multiple builder scripts (that are mostly
identical) strikes me as a particularly inelegant solution that
complicates the Perl expression significantly. The expressions for 5.8
and 5.10 contain a lot of redundancy already -- I didn't want to
complicate that even further. IMHO, there is a trade-off between
short-term costs and long-term benefits at work here:

 * The simple patch is easier to maintain, but expensive in terms of
   re-builds performed now.

 * The complex patch doesn't cost anything now, but is harder to
   maintain in the long-term.

Anyway, I would like to use nixpkgs-trunk on Darwin. For the time being,
I'll just keep the necessary changes to my local repository until things
have stabilized a bit. At that point, we can figure out how to merge
them. It was probably a mistake to commit those changes to the central
SVN repository right away. If I have inconvenienced anyone, then I am
sorry.

Take care,
Peter