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.core/src/org/eclipse/jdt/internal/junit/util/TestSearchEngine.java
private class JUnitSearchResultCollector extends SearchRequestor {
		List fList;
		Set fFailed= new HashSet();
		Set fMatches= new HashSet();
		
		public JUnitSearchResultCollector(List list) {
			fList= list;
		}
		
		public void acceptSearchMatch(SearchMatch match) throws CoreException {
			Object enclosingElement= match.getElement();
			if (!(enclosingElement instanceof IMethod)) 
				return;
			
			IMethod method= (IMethod)enclosingElement;		
			
			IType declaringType= method.getDeclaringType();
			if (fMatches.contains(declaringType) || fFailed.contains(declaringType))
				return;
			if (!hasSuiteMethod(declaringType) && !isTestType(declaringType)) {
				fFailed.add(declaringType);