Since you are intending "to determine if QT is good or bad", Just to be clear on something...
Qt is a C++ framework/library with an object oriented API.
Qt is not a programming language.
Qt is not a compiler.
Qt is not a debugger.
Qt Creator is an IDE which is provided to help organise your tools to build your projects.
As others have said it looks like your tools, in this case the debugger is at fault.
Please do evaluate it in that light and people on this forum will be more than pleased to help you.