[CMake] CMakeCache.txt, MSVC generator, and automatic re-configuration

[Clifford Yapp]

I noticed when doing a recent test of our build with CMake 2.8.8 and
MSVC that the CMakeCache.txt file seems to be getting changes applied
to it during the generation step (primarily a lot of additions with
the comment "Stored GUID", seemingly related to custom
commands/targets.)  One of the things I've noticed when doing Windows
builds is that it seems to be very important that the CMakeCache.txt
file after Configure/Generate not be in a state that triggers an
automatic re-running of CMake "out of the box" in MSVC - we have
hundreds of build targets and the interactive prompting is a killer
for usability.  From what I have seen previously, it looks like this
automatic re-run takes place whenever the CMakeCache.txt file changes
after the "Configure" step is complete.  That was previously happing
due to quirks with our build, but we had found ways to avoid the
problem and were getting a "clean" MSVC build with no CMake
re-running. I don't recall seeing this "Stored GUID" content appearing
in the generator step previously - is this new?

Any help appreciated.
CY