Warning in <MyClass>: The data members of MyClass will not be stored, because it inherits from TObject but does not have its own ClassDef

[ferhue]

Hmmm, but I do not have any LinkDef file in my CMake project.

As I just wanted a minimal GUI class deriving from TGMainFrame, I call the ROOT_GENERATE_DICTIONARY without using the LINKDEF argument, as done here:

Classdef

As Philippe pointed out, you need to link against the generated dictionary of our class. Just changing slightly the CMakeLists.txt file like this should work. cmake_minimum_required(VERSION 2.8) project(tbjcAnalysis) list(APPEND CMAKE_PREFIX_PATH $ENV{ROOTSYS}) find_package(ROOT) include(${ROOT_USE_FILE}) include_directories(${ROOT_INCLUDE_DIRS}) add_definitions(${GCC_COVERAGE_COMPILE_FLAGS}) include_directories(${PROJECT_SOURCE_DIR}/include) ROOT_GENERATE_DICTIONARY(G__test include/test.h)…

Or is it a bad practice not to specify a LinkDef?