Qbs is being unnecessary called when building Creator with cmake

1. Make sure the Qbs build is enabled in the Qt Creator (CMake based) build (submodule src/shared/qbs is checked out, and BUILD_QBS=ON (which is the default))
2. Build Qt Creator including Qbs with CMake
3. Touch some source file of your Creator build and do:

cmake --build . --parallel

4. The output is like that:

[3/3] cd /home/jarek/dev/creator-415-build-515/src/shared/qbs...-515/src/shared/qbs/ config:resources-build -p qbs\ resources
Restoring build graph from disk
Resolving project for configuration resources-build
Restoring build graph from disk
Building for configuration resources-build
Build done for configuration resources-build.

It means that qbs process is being executed while cmake is building Creator.

qbs shouldn't be (re-run) if only Qt Creator files are touched.