How do I run xctest from the command-line with Xcode 5?
Despite what the usage message says -XCTest is the argument you need:
xctest -XCTest MyAppTests/testExample testbundle.xctestFor a direct invocation of xctest to work you may also need to set DYLD_FRAMEWORK_PATH and DYLD_LIBRARY_PATH to your built products directory. In general you need to use the same arguments and environment as Xcode does, you can see this by putting a breakpoint in one of your tests, running them through Xcode, then printing out the values of arguments and environment for [NSProcessInfo processInfo].
To avoid messing with all that note you can also modify the scheme in Xcode to run only specific tests. Under Product > Scheme > Edit Scheme select the Test action and expand the test bundle. You can use the check boxes to select the tests to run and xcodebuild's test action will then run only these tests.