[CMake] Complete rebuild after svn update

[Alex Brooks]

Hi,

I have a problem where cmake decides to rebuild my entire source tree when an 
svn update pulls in a change to a CMakeLists.txt file.

I have a fairly complicated build tree with a number of sub-libraries etc.  
The whole thing takes something like an hour to build, so it's a big chunk out 
of my day.

I tried a few things to characterise the problem:
  - If I locally touch CMakeLists.txt files, or even make non-trivial changes, 
cmake does the correct thing and just rebuilds what is necessary.
  - If an svn update pulls in a changes to .h or .cpp files, cmake again does 
the correct thing.
  - If an svn update pulls in even a trivial change (e.g. a change to a 
comment), cmake rebuilds every single source file.

I've run out of ideas about how to characterise the problem better, does 
anyone have any ideas what the problem might be, or what to do next to track 
it down further?

My CMake version is 2.8.2, and I'm using Makefiles on Linux.


Thanks in advance,

Alex