Unable to debug when Run in Terminal option selected

Refer "Tests using tests/manual/debugger/cli-io/cli-io.pro from Qt Creator's source repository" section in https://wiki.qt.io/Qt_Creator_ManualTests_DebuggerLldb

>> When Run in Terminal option is selected, it was not possible to debug. What is the expected behaviour? Is it possible to debug when Run in Terminal option selected?

>> Output when Run in terminal selected  : 

This is a QString: "I'm a QString"
This is a std::string: I'm a std::string
This is a char c[]: I'm a char c[]
This is an int: 1892
This is QDebug
This is stdout
This is stderr

Observation :  Order of output statements is same as code.

Output when Run in terminal option not selected :

This is a QString: "I'm a QString"
This is QDebug
This is a std::string: I'm a std::string
This is a char c[]: I'm a char c[]
This is an int: 1892
This is stdout
This is stderr

Observation : The order of output statements appears to be different. Could you please confirm why the behaviour is different in both cases?