MumbleKit library produces no .a target

I included the MumbleKit library in a project and all seems to compile correctly; yet none of the 3dparty libraries, nor main mumblekit library produces its .a target. I even tried compiling 3dparties library Speex individually and again no error, but no target. Another project with seemingly the same configuration produces the .a files without any problem and so I have no cue about what might be wrong in the new one; the following image shows the situation for the two projects after compiling both:

The issue was apparently to enable the all architectures flag both in the main mumblekit target and in all the dependent ones. The libraries remain red for some strange reasons. Yet everything seems working inclusing the usage of the mumblekit features.