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/JUnitMainTab.java
return null;		
	}
	
	/**
	 * Return the IJavaProject corresponding to the project name in the project name
	 * text field, or null if the text does not match a project name.
	 */
	protected IJavaProject getJavaProject() {
		String projectName = fProjText.getText().trim();
		if (projectName.length() < 1) {
			return null;
		}
		return getJavaModel().getJavaProject(projectName);		
	}
	
	/**
	 * Convenience method to get the workspace root.
	 */
	private IWorkspaceRoot getWorkspaceRoot() {
		return ResourcesPlugin.getWorkspace().getRoot();
	}
	
	/**
	 * Convenience method to get access to the java model.
	 */
	private IJavaModel getJavaModel() {
		return JavaCore.create(getWorkspaceRoot());
	}
	/**
	 * @see ILaunchConfigurationTab#isValid(ILaunchConfiguration)