[CMake] Repeated Cmake runs with ParaView on OsX with Ninja CMake 2.8.12.1

[Utkarsh Ayachit]

I'm seeing a strange behavior since I updated to CMake 2.8.12.1. On my
OsX Lion machine, with Ninja generator, when building ParaView, if I
modify a CMakeLists.txt and then  run "ninja" in close succession
twice without any other changes, CMake is run both times!

The second time, if I do "ninja -d explain", I get the following:

ninja explain: output build.ninja older than most recent input
/Users/utkarsh/Kitware/ParaView3/ParaViewBin/bin/paraview.app/Contents/MacOS
(1388251354 vs 1388252403)

Any ideas on what could be wrong? Is it ParaView's CMake rules or some
issue in Cmake?

Utkarsh