My case is simple, a workspace with two sibling projects: one main (iOS) app and a project that builds several static library targets used by the app.
Here\'s how I
In my case, the only way i could have that sibling configuration build is by manually adding the path "../MyLibProject/build/Debug-iphoneos" (checking recursive just to make sure) in my Build Settings -> Library Search Paths. Adding the .a file in the Main project alone didn't prevent the "lib not found" error at link time.