Using OSX and iOS SDKs in a single C++ Xcode 6 project

I am building a C++ static library used on both iOS and OSX that is built with Xcode 6.2.

I tried to make a single project with two targets: one based on the iOS SDK, and another based on the OSX SDK (implemented by overriding the project-level iOS SDK setup).

They both build OK, but the "Products" group in the Project Navigator only can find the output library for the SDK selected in the "Project" settings (not the targets). That is, the Project-level "Base SDK" selected seems to window down what XCode can find in the "Products" output targets display.

Am I going the wrong way here? Should I be doing 2 separate projects (and maybe combining them with a workspace) instead? It seems like using both SDKs in one project isn't fully baked.