Debugging on Windows is broken (QtCreator 3.4)

I experienced various debugging problems on Windows when trying to debug:
(in RC1 and then I downloaded a version from here https://download.qt.io/official_releases/qtcreator/3.4/3.4.0/)

1) A Qbs MSVC console project:
This does not seem to be a "Debug" build.

2) A Qbs MinGW project when I set a breakpoint:
The inferior stopped because it received a signal from the operating system.

Previously (Qt Creator 3.3) I was able to debug and set breakpoints even in Assembler files.

I have attached the test project I am working on but please be aware that it is incomplete and it might not work for all build variants.

EDIT:
1) and to 2) also occur with a regular Qt project (as seen on the screenshots).