Bug 49484 "Errorless" Launch Config fails [JUnit]
Create a JUnit Launch configuration. On the Test tab 1) Be Sure "Project" is an empty field. 2) Select "Run all tests in the selected project, package or source folder". 3) Select the Project to search for tests. 4) Click Run The Progress view shows "ERROR: Launch: invalid project specified" If you specify the Project field, even without "Run a single test" being selected, it works. I don't know what will happen if the Project doesn't match the selection in "Run all tests..." 3.0 M6
org.eclipse.jdt.junit/src/org/eclipse/jdt/internal/junit/launcher/JUnitBaseLaunchConfiguration.java
TestSearchEngine.doFindTests(new Object[]{container}, result, pm);
			 
			filterNonProjectTests(javaProject, result);
		} catch (InterruptedException e) {
		}
		return (IType[]) result.toArray(new IType[result.size()]) ;
	}
	private void filterNonProjectTests(IJavaProject javaProject, Set result) {
		for (Iterator iter= result.iterator(); iter.hasNext();) {
			IType type= (IType) iter.next();
			if (!type.getJavaProject().equals(javaProject)) 
				iter.remove();
		}
	}
	public IType[] findSingleTest(IJavaProject javaProject, String testName) throws CoreException {
		IType type = null;
		try {
			type = findType(javaProject, testName);
		} catch (JavaModelException jme) {
			abort("Test type does not exist", null, IJavaLaunchConfigurationConstants.ERR_UNSPECIFIED_MAIN_TYPE); 
		}
		if (type == null) {
			abort("Test type does not exist", null, IJavaLaunchConfigurationConstants.ERR_UNSPECIFIED_MAIN_TYPE); 
		}
		return new IType[]{type};
	}
	
	/**
	 * Throws a core exception with the given message and optional
	 * exception. The exception's status code will indicate an error.