[CMake] Propagating variable to toplevel parent

[Mathieu Malaterre]

Hi there,

  I am wondering if I am missing anything here. How would one
propagate a variable across subdirectories in cmake ? I thought that a
simple CACHE variable would do the trick, but using cmake 2.8.1 I had
to do the following trick

list(APPEND v "42")
# make sure to actually update the CACHE variable:
set(v ${v} CACHE INTERNAL "toto")

My goal is that at the end of the toplevel cmakelists.txt file, cmake
would have collected a list of installation path.

Thanks for comments,
-- 
Mathieu

ref:
https://gdcm.svn.sourceforge.net/svnroot/gdcm/Sandbox/CMakeBug/13/