Xcode 4 - how does it know what build configuration to use for nested projects?

First time poster, this site is invaluable for answering my questions - so thanks to everyone who contributes!

I have an Xcode 4 project with multiple nested projects (which build as libraries for the main project). Everything is working 开发者_如何学JAVAfine but one step baffles me:

How does it know what configuration to build (and link) for the nested projects? For example my main app has a Distribution configuration. I want it to build and link against the nested projects' Release configurations. And it does!!! but how does it know that? I can't find anywhere where I would specify it.

After scouring the internet to no avail - I'm thinking it might be using magic...

I may have a solution to your question:

If you look at the scheme settings of your included frameworks, they by default have defined Release as configuration to use when you build for Archive. Would be possible that Xcode uses this setting when you build your main project for Archive (and would actually make sense).

(For me this doesn't work, won't find the headers, maybe you have an idea?)