Xcode settings: architecture and virtual architecture

Question

I looked at the configuration of the Sparkle project and noticed that they installed:

• Architectures = ppc i386 x86_64
• Valid architectures = i386 x86_64

Description of valid architectures from apple:

A list of identifiers separated by spaces. Defines the architecture for which binary can be built. At build time, this list intersects with the ARCHS setting value; the resulting list indicates the architectures on which the binary can run. If the result of the Architecture List is empty, the target does not generate a binary file.

So, why install architectures other than valid architectures if they don’t work on ppc at all?

Answer 1

If set to “Built-in assembly device architecture,” you can specify which architecture your application works with.

For example, if you have an application that is not ready for a 64-bit environment (it can be compiled, but it will crash), you will set the valid architectures to only 32 bits, so it will not build a 64-bit section even to 64 bit computer.

Regarding your Sparkle question - you will need to ask the Sparkle developers, but I'm sure this is just a value that comes from the days when PPC is still widely used.