Debug any application and Switch on temporarily 'Operate by Instruction' (small icon above the stack trace) and check whether you see disassembler output and can step by instruction.
Refer https://wiki.qt.io/Qt_Creator_ManualTests_DebuggerLldb. for detailed test case
The behaviour is inconsistent. Sometimes it displays disassembler code, sometimes it doesn’t.
Eg:
The disassembler output is not displayed for simple.pro project , but for cli-io/cli-io.pro it is displayed.