Qgroundcontrol forces complete rebuild on single file update

I use master branch of Qgroundcontrol and I observed a weird issue with dev setup.
QGC got built successfully. I updated the VehicleComponent.cc file and QGC started building from scratch .
It takes lot of time when it rebuilds.
I didn’t observe this behavior when I updated the MainRootWindow.qml file.
Please provide solution for this problem.

Usually the compiler will only recompile the necessary file unless you force it to rebuild the whole project. However even though there is only one file modified, but the other file that depends on the modified file will also need to be rebuild. In this example the VehicleComponent class is included by about other 20-30 classes, and there could also be other class depends on these classes as well, which leads to rebuild lot of targets.
On the other hand, the qml file is a kind of out of box thing since the purpose of qml is trying to split the interface part and the “core” part of a program. So usually if you only modify some qml file, it will take much less time to compile.