Hmmm... If anything you should at least place it in CXXFLAGS. I mainly didn't include it in the CXX flags because a lot of tutorials/references I used didn't do that. They might have had some other cool tricks to make up for it though. I do see your point. The way we had it set up gdb would only tell you which file but not which line of the file because it did not have the debugging info generated for the files.