xcode 4 fails to initiate unit tests (with linker error) after I created a new scheme

Question

My unit tests worked fine in xcode4 until I had to create a new schema to compile a package to run on my device for testing.

All I did was creating a new Target an

Answer 1

We were using nodejs-mobile which would build with the app but fail building with the tests.

Undefined symbols for architecture x86_64:
  _start_node

In addition to all of the previous answers (build settings, search paths, making a brand new Unit Test, deleting DerivedData), what finally resolved it was creating a brand new new UI test instead of a Unit Test in Xcode.

It built successfully. Then you can copy your test definitions from your current test to the one one.

If you do not need the UI part, you can uncomment XCUIApplication().launch() in setUp of the generated tests, which makes it run as fast as before.