No architectures to compile for (ONLY_ACTIVE_ARCH=YES, active arch=x86_64, VALID_ARCHS=armv7 armv7s)
You can set the "Build Active Architecture Only" and "Archs" values from command line itself. We set ARCHS="armv7 armv7s" ONLY_ACTIVE_ARCH=NO.
Eg
/usr/bin/xcodebuild ARCHS="armv7 armv7s" ONLY_ACTIVE_ARCH=NO -workspace -scheme ......
This will free you from manually changing the values in your project settings.
In my case it was empty cell in the 'valid architectures' on the target level which resulted in empty 'resolved' cell.
That lead to empty 'valid architectures' parameter and at the end linker error.