Qt Creator integration with Visual C++ is broken since Qt 5.4 / Creator 3.3.2

[Violet Giraffe]

At least it's broken for me; I doubt it's a bug that affects all the Windows users or it's be fixed by now.
Generating VS project with qmake -tp vc works fine. But building from Qt Creator does not. When I launch build, all I get is "'cl' is not recognized as an internal or external command". Another side effect is that all the system and standard library includes are not found, so editing code with Creator became very inconvenient as well.

The Qt kit seems to be configured properly, I can't see any problems: Under compilers, among other entries, I have the desired Microsoft Visual C++ Compiler 12.0 (x86) (I use Qt 5.4.1 for MSVC 2013 with OpenGL). The Initialization command for this compiler is the correct C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\vcvarsall.bat x86. The path is correct, and if I execute this script in a console, I can run cl no problem.
And the kit, Desktop Qt 5.4.1 MSVC2013 OpenGL 32bit, is set to use this compiler - MSVC 12.0 x86.

What could be the problem?

P. S. Everything worked fine before I upgraded to Qt 5.4 and the corresponding version of Creator.