My project is built by builbot using cmake and the Visual Studio C++ compiler.
Using "Visual Studio 14 2015 Win64" as generator it works but it builds slowly and I have difficulties to find the source of an error (this is another problem).
So I want to try Ninja but when I set it as the generator it selects the GNU C++ compiler. I found that I should load the vcvarsall.bat before calling Ninja but I don't understand how to do it from buildbot.