[CMake] Variables propagating upwards

[Lachlan Gunn]

Hi,
I have been working on a project that makes use of  CMake, and a
problem has come up during the course of development.

When I set a variable in a lower-level CMakeLists.txt file, it does
not propagate upwards into the parent CMakeLists.txt file.  Example:

src/CMakeLists.txt
-------------------------
SET(VAR foo)
ADD_SUBDIRECTORY(foo)
MESSAGE("=${VAR}=")

src/foo/CMakeLists.txt
-------------------------------
SET(VAR bar)
-------------------------------

The above will give an output of "=foo=", with an expected output of
"=bar=".  Could anyone point me to the relevant documentation please?
-- 
Thanks,
Lachlan