ld: file not found: linker command failed with exit code 1

You might be getting this error because you renamed your project and Tests cannot be found anymore. This is easy to fix:

Solve it in Xcode like this:

1. Select your project from the project navigator.
2. Select [Your project's Tests] under targets
3. Under General tab change the Host Application from the drop down
4. Build and run.

This problem happened to me because I renamed my project and the tests could’t find it anymore.