Linker Error When Accessing Application Module in UI Tests in Xcode 7.1

UI Tests Mach-O Linker error

Your problem is not easily solvable at the moment... You gotta do crazy things to get around that limitation, such as: Include all your code in your UI test target.... or provide ways to access the logic you want exposed, from the UI Layer so it can trigger things inside your app. i.e. A Button that resets all your data layer... fakes network connectiviy... whatever your test is.

Check this answer for more details and the different strategies to solve that problem:

Linker error when accessing application module in UI tests in XCode 7.1

iOS UI Tests Linker Error

For some reason, when I created my UITest target, a linker flag was added in the target that shouldn't have been there (-lMySDK).

Removing that flag resolved the linker error.

Mach-O Linker Error When Adding Unit Tests - XCode

You have to add AudioUnit framework to your project first and then rebuild it.

This is how you add frameworks to your project.

UIColor Category Linker Errors

The linker error indicates that you are using CoreGraphics functions but you are not linking the CoreGraphics framework.

Update your project/target so you link the CoreGraphics.framework and the linker issues will be resolved.

Linker error when compiling PJSIP on iOS 7 sdk and xcode 5

You can download prebuilt pjsip library (armv7, armvs7, arm64, i386) from cocoapods using pod 'pjsip' or by compiling it by yourself running build.sh script from https://github.com/chebur/pjsip