void reportError(String msg, Element e) {
        messager.printMessage(Diagnostic.Kind.ERROR, msg, e);
    }
Issue a compilation error. This method does not throw an exception, since we want to continue
processing and perhaps report other errors. It is a good idea to introduce a test case in
CompilationTest for any new call to reportError(...) to ensure that we continue correctly after
an error.

@param msg the text of the warning
@param e   the element to which it pertains
android/annotation_processors/xposed_hook_compiler/src/main/java/github/tornaco/permission/compiler/ErrorReporter.java