[CMake] VS2012 builds using v3.1.0 are a lot slower than v2.8.12

[Paul Smith]

> Am 20. Januar 2015 14:54:26 MEZ, schrieb David Cole via CMake
> <cmake at cmake.org>:
> >If you open the "Tools > Options" dialog in Visual Studio, and
> >navigate to the "Projects and Solutions > Build and Run" tab, what is
> >your "maximum number of parallel project builds" value?
> >
> >For maximum parallel build capability, it should be set to the same
> >as the number of cores you have.

On Tue, 2015-01-20 at 17:30 +0100, Hendrik Sattler wrote:
> but msbuild does not use this setting from VS, only devenv does.

So, I've discovered we're having this problem as well... on 3 of our 6
Windows build servers!!

Looking at the logs I can see that on systems where it's "slow", "cmake
--build" is choosing to use msbuild (and we don't have any added flags
to have it run in parallel).

On the other three systems where the build is "fast", "cmake --build" is
choosing to use devenv (and is building in parallel by default).

All these systems have Visual Studio 2010 and Visual Studio 2008
installed, but we invoke the builds on them identically in all cases
(and these builds are using a generator of 'Visual Studio 10 x64').

Where can I go to find out more about how cmake --build chooses whether
to use msbuild vs. devenv?  It has to be something more complicated than
just the generator used, otherwise all of these systems would use
msbuild.


FYI, I'm using CMake 3.1.0.