Running Unit-Tests for a non-simulator / device architecture

I am appointed the task of making unit-tests for an SDK. Unfortunately I get the following error when trying to run a unit-test in the simulator:

ld: warning: ignoring file /Users/joeribultheel/Documents/Projects/Ios/plop-plopplop-ios/V3MockSDKTest/plop-plopplop-ios.framework/plop-plopplop-ios, missing required architecture x86_64 in file /Users/joeribultheel/Documents/Projects/Ios/plop-plopplop-ios/V3MockSDKTest/plop-plopplop-ios.framework/plop-plopplop-ios (3 slices) Undefined symbols for architecture x86_64: "_OBJC_CLASS_$_Wrapper", referenced from:
  objc-class-ref in V3MockSDKTestTests.o ld: symbol(s) not found for architecture x86_64 clang: error: linker command failed with exit code 1 (use -v to see invocation)

I tried running the unit-tests on a physical device but no luck. Is this even possible? I tried with the default project-generated unit-test and it doesn't seem to work either.

In short: how can I unit-test code written for a device-architecture only ?

Thank you!