[CMake] binary directory?

[Jack Andrews]

i'm getting this error:

>cmake -G "Visual Studio 8 2005"
CMake Error: Error in cmake code at
C:/cygwin/home/jack/play/d/CMakeLists.txt:1:
ADD_SUBDIRECTORY not given a binary directory but the given source
directory "C:/cygwin/home
/jack/play/bdwgc" is not a subdirectory of
"C:/cygwin/home/jack/play/d".  When specifying an
 out-of-tree source a binary directory must be explicitly specified.
Current CMake stack:
[1]     C:/cygwin/home/jack/play/d/CMakeLists.txt
-- Configuring done


the first line of my CMakeLists.txt is:
ADD_SUBDIRECTORY(../bdwgc)


is there a way to include the project defined in this sibling
directory in the solution?


ta, jack