Will binaries built in 10.6 still run in 10.5?

[Nikos Chantziaras]

On 10/04/2010 03:44 AM, Ryan Schmidt wrote:
> On Oct 3, 2010, at 17:15, Nikos Chantziaras wrote:
>
>> I noticed (by means of ps) that when ports builds something, I see this flag passed around: "-mmacosx-version-min=10.6" :-/  Am I in trouble?  I need the binaries to work on 10.5 too.
>
> Then you need to set that in macports.conf. This was discussed here recently:
>
> http://lists.macosforge.org/pipermail/macports-users/2010-September/021880.html
>
> Note that this won't necessarily work for all ports. The most reliable way to get software built that runs on e.g. 10.5 is to build it on 10.5.

I tried this and added "macosx_deployment_target 10.5".  However, the 
wrong compilers are used then.  Instead of:

   /usr/libexec/gcc/i686-apple-darwin10/4.2.1
   /usr/libexec/gcc/ppc-apple-darwin10/4.2.1

for Intel and PowerPC respectively, these are used:

   /usr/libexec/gcc/i686-apple-darwin10/4.0.1
   /usr/libexec/gcc/ppc-apple-darwin10/4.0.1

Is there a way to change that and use 4.2.1?  AFAIK, 4.0.1 is only for 
OS X older than 10.5.  When "macosx_deployment_target 10.5" is set, the 
compiler should be 4.2.1.