Reinstall all ports after Xcode 4.1 -> 4.2 upgrade?

[Jeremy Huddleston]

On Nov 23, 2011, at 09:45, Brandon Allbery wrote:

> On Wed, Nov 23, 2011 at 08:36, Christoph Deil <deil.christoph at googlemail.com
>> wrote:
> 
>> I just updated XCode from 4.1 to 4.2 on Lion.
>> Do I have to reinstall all ports because the XCode compilers changed?
>> 
> 
> No; the APIs and ABIs are still the same.  It's when Apple changes those
> (as with a new OS release) that you need to forcibly rebuild stuff,

That's not entirely true.  We take great effort to ensure that we don't break existing APIs.  There will be new APIs added, but existing APIs and ABIs should be entirely compatible.  If you use your Leopard-built or SL-built MacPorts on Lion, it'll work fine.  The "problems" have traditionally been when upgrading from an i386 MacPorts to an x86_64 MacPorts or similar such changes.

> because
> Apple tends to move things around a lot (for example, in Lion a bunch of
> stuff apparently moved out of libSystem.dylib to other libraries).

This is not true.  Things did not move out of libSystem.  libSystem just became an umbrella library rather than a monolithic library, but everything is still there.  If they had moved out of libSystem, then every existing application would break.