If you have an Xcode project that includes another subproject and you have defined custom build (for e.g., I often define
Adhoc) configurations on top of the default Debug and Release configurations, be prepared for an error while building using custom build configurations.
What happens is Xcode will build the subproject(s) using the same build configuration name, e.g. if I build
Adhoc, Xcode will try to build
Adhoc for the subproject too and failing which, fallback to
Release. This might not be what you want.
The easiest fix is to modify your subproject so they have the same custom build configurations.